Vitamin D: Blatant Cash Grab or Skeleton Key to Amazing Health?

You will probably agree on this:

… there are so many Vitamins on the market that it’s hard to know which is the right one.

Further more all the science papers are written as if they were in a foreign language.

Are you left with a random choice and hope for the best?

Well, this article was created to help you.

It will simplify scientific jargon. And it will guide you to an improved health in 60 days or less.

Without any further ado you will find out exactly what you need to know about Vitamin D.

There are interactive maps to aid understanding. You will also find calculators to figure out the right dose for you.

All this and more is detailed below. Let’s dig in.

​Table of Contents:

You have been misled Vitamin D is more important than you have been lead to believe!

How do I know if I’m Vitamin D deficient?Can you cure anxiety and depression with regular Vitamin D supplementation?

All those diet plans failed, maybe Vitamin D can stop Obesity?

Is Vitamin D the influenza, cold buster?

What’s the optimal range for Vitamin D3?

What’s the optimal range for Vitamin D3?

What’s the best supplement to combat deficiency?When should I take Vitamin D?Should I take D2 or D3? What’s the difference between the two vitamins?

Can you overdose using Vitamin D3? What are Toxicity symptoms?

You have been misled Vitamin D is more important than you have been lead to believe!

Sunshine Vitamin

Vitamin D, aka the Sunshine Vitamin, or the most necessary vitamin for bone health.

Before my journey to learn everything there is to know, these were the things I believed. After reading countless research papers and studies, I’ve learned that it’s much more than a simple vitamin.

Did you know ​Vitamin D is at least 1 billion years old?

Microorganisms were creating Vitamin D with the help of the sun.

It has been proven that Vitamin D helps Ca (Calcium) absorption. Recent studies show it increases Ca intake by 25X.

Let’s go back in time before dinosaurs roamed the earth. For microorganisms to grow and inhabit different lands, they needed a strong shell. Ca was available, so with the help of Vitamin D, the absorption rate was increased.

The skeletal frame and all the bones are made out of Ca. With the help of the sun, these organisms have evolved to fish and then to reptiles and to dinosaurs. The evolution didn’t stop there; it continued to mammals and eventually to human beings.

If you are interested in an animated version of this story, check out Dr. Holick’s presentation (he’s the #1 in the field of Vitamin D science, for over 40 years he has been researching it).

Dr. Holick has a hypothesis about the extinction of dinosaurs. He believes a meteor hit the earth and the impact blocked out the sun. All the dinosaurs died from lack of Vitamin D. Nocturnal rodents survived because they didn’t need it.

Since the early 1800s, hundreds of physicians noticed that some children develop rickets. Rickets is a disease of the bones. The bones don’t have the necessary toughness, so they bend.

The physicians noticed that city kids are more likely to have this disease compared to children who live on farms. The conclusion was that the lack of adequate sunshine is the cause.

It took more than 100 years for Vitamin D to hit the news. Almost every day, there is a new study coming out showing the link between Vitamin D deficiency and some kind of illness: high blood pressure, obesity, anxiety, depression, dementia, inflammation, testosterone, multiple sclerosis and immune system to name a few.

Let’s travel back in time again. This time, we only go a few thousand years into the past. Our early ancestors were hunter gatherers. They were out in nature all day. Then the agricultural revolution happened.

Dr. Holick has an interesting view on the migration of mankind. He believes that only those human species who had adequate exposure to sunlight and ate Ca rich foodssurvived. If the females didn’t have strong enough bone structure for the birth canal, then they couldn’t give birth to viable offspring. Thus the whole species dies out.

People have stopped migrating, but they were still outside in the sun. Fast forward some years and the industrial revolution happened.

People started to migrate into cities. We all know early cities were unhealthy, to say the least. Besides the migration towards urban areas, people started to work in factories. This meant they were working 8-12 hours a day indoors.

Their exposure to sunlight has been cut dramatically. Since the industrial revolution, different diseases have popped up. Scientists have linked many of these to the lack of D3 vitamin.

That’s it for the history lesson. Further along, you will find out how Vitamin D is created, if the sun is safe, and how you know if you have a deficiency.

How is Vitamin D3 naturally created in the human body?

​When I started this journey, I had to brush up on my old chemistry knowledge just to make sense of it all.

This article will be different. I will try to avoid all the technical mumbo jumbo. As Einstein said it best: “If you can’t explain it to a six-year-old, you don’t understand it yourself.”

​As Barney Stinson would say:

The sun emits three different types of ultra violet rays:

UVC – this bounces off the Ozone layer and never reaches the earth’s surface. It’s artificially created and used in sanitation

UVB – this penetrates through the Ozone layer and makes contact with the skin, which leads to the production of Vitamin D.

UVA – this wave length is omnipresent. Even if there are clouds, these rays pass through them. UVA is the culprit that causes redness and sun burn.

UVB is the good guy. When the skin is exposed to these rays, it produces Vitamin D3 from cholesterol. This is the same vitamin you get from supplementing.

After D3 is created, it is transported to the livery, and it’s transformed into the active form. D3 is actually turned into a hormone.

Vitamin D also known as Cholecalciferol

Scientist have recently found that most cells in our body have Vitamin D receptors. This shows that it’s not just for bone health. It has wider uses.

This is the easiest way to explain the creation of Vitamin D3 and its role in our body.

So far, we have covered the history of Vitamin D and how you can obtain it naturally.

All we have to do is go outside, soak in the sun, and we’re not deficient in Vitamin D anymore?

Sorry to disappoint, but it’s not that simple. Many things influence how much you can synthesize.

As I mentioned, only UVB is beneficial for your health. The factor you need to consider is the season.

During summer, there’s an abundance of UVB. During the winter months, the sun might shine, but there aren’t any UVB rays coming through.

​   USA UV Index During The Seasons (Animated Map)

You probably know that, during the winter months, we are actually closer to the sun than during the summers. Why is it cold during the winter if we are closer to the sun?

Everything comes down to the angle. During the winter months, the Earth is tilted away from the sun. This means the amount of solar radiation hitting the Earth is reduced because of the angle.

Scientists proved, during the winter months, November – March, there is minimal or no D3 synthesis going on. Not enough UVB radiation is coming through.

​Here’s the human friendly title: How much Vitamin D is created on a monthly basis

The next factor you need to consider is the distance from the Equator. The closer you are, the more UV radiation you are exposed to.

Dr. Holick did an experiment comparing UV radiation between Boston and Miami. You might be shocked about the amount of time you have to stay in the sun to get 1,000 IU of Vitamin D.

You need to know that the darker your skin complexion, the longer you have to stay in the sun. Here are the results.

Both measurements were made at noon. Most UVB comes through during this time of day.

​How Much UVB You are Getting In the South Vs. North


​Skin ​Complexion





​6 Minutes

​15 Minutes


African American

​15 Minutes

​29 Minutes



1 Hour



African American

​2 Hours


​In just six minutes in Miami, you can get 1,000 IU worth of Vitamin D3 (the recommended minimum is 600 IU a day). Meanwhile, if you are living in Boston, the same amount is generated in 60 minutes. That’s a 10X factor difference.

If you have a darker skin color, you have to stay out even longer.

During winter in Boston, you have no chance to synthesize Vitamin D3. This experiment clearly shows the importance of geographical location.

The further you live from the Equator, the less UVB is available.

The amount of UVB is determined by the season and your location on the globe.

Another factor you need to take into account is the color of your skin. The paler you are, the faster you synthesize the vitamin. On the other hand, if you have darker skin tone, then you need to be out longer.

This got complex fast. I promise you this is the last factor. The amount of UVB you can convert comes down to the amount of skin you are exposing to the sun.

Here’s an estimated amount on how much UVB you can convert dressed in different clothes.

​Dress Mode

11% Sun Exposure

If the sun is hitting your arms and ​hands you are converting at 11% (wearing T-shirt, slacks, sun glasses and a hat)

11% Sun Exposure

18% Sun Exposure

If the sun is hitting your face, arms and hands you are converting at 1​8% (wearing T-shirt, slacks, sun glasses and ​with no hat)

18% Sun Exposure

32% Sun Exposure

If the sun is hitting your face, neck, arms, hands and ​lower legs you are converting at ​32% (wearing T-shirt, slacks, sun glasses and ​with no hat)

32% Sun Exposure

5​3% Sun Exposure

If the sun is hitting ​the top half of the body you are converting at ​53% (​stripped to waist)

5​3% Sun Exposure

73% Sun Exposure

If the sun is hitting ​the ​whole body except for one piece bathing suit you are converting at ​​73% (​ladies)

73% Sun Exposure

88% Sun Exposure

If the sun is hitting ​the ​whole body except for swim suit (man) and bikini (ladies) you are converting at ​​​88%​

​88% Sun Exposure

​As the Earth rotates, a sun’s rays are reflected by the ozone layer. For you to get the needed Vitamin D3, you should be out in the sun between 10:00am and 3:00pm according to Dr. Holick.

One good rule of thumb to follow is the measurement of your shadow. If it’s shorter than your height, then the sun is at the right angle, and you are exposed to the most ultraviolet B.

Last but not least, your age is an important factor in D3 vitamin synthesis. The older you are, the harder it will be to create D3. According to Dr. Holick, a 20-year-old creates 4x more D3 than a 60-year-old. This means that, as we age, either increase the sun exposure or supplement more.

Can I get the necessary ultraviolet B exposure indoors or in the car?

If you are behind any kind of glass, only UVA will pass through. UVA has a longer wavelength, so it passes through glass with ease.

UVB has a short wavelength and can’t penetrate glass. It happened to me countless times when I was driving for long periods of time in the summer. The certain parts of my skin that were exposed to sunlight got pinkish, almost burned.

Here’s a scary example of exposure to UVA radiation.

His Left Side is Damaged Source:

​On the picture, you can see the face of a truck driver. He has been driving long distances for 28 years. One side shows natural aging, and the other side shows excessive damage.

Now, don’t run and get sunscreen just because you are next to a window. Remember he was driving many long hours for numerous years.

This can happen to the body if it’s exposed to UVA and only UVA for long periods of time.

How do I know if I’m Vitamin D deficient?

​There’s only one way for sure, by doing a blood test. You can specifically ask to measure your D levels.

Vitamin D deficiency is subtle, and in most cases, it passes unnoticed.

Here are ten signs that you’re most likely to be deficient:

1. Frequent sickness:

Over a lifetime on average: Men have 140 sick days Women call in 189 days

As soon as the cool season hits, are you in and out of sickness?

Then this might be a sign you are lacking the necessary D3 to fight disease.

I remember, before learning about supplements and vitamins, I got sick all the time. As soon as I started with the right doses, I was healthy. My longest stretch was 5 years in a row. No flu, no cold, nothing.

Did I mention that I work with children?

I believe, if the immune system is strong, then it can fight most common illnesses.

For some odd reason, I got a cold in August. Probably the lucky streak ends now and then.

Why did I fall ill?

My best guess would be a lot of stress and an active toddler who has bad sleeping habits.

2. Depression:

18.1% of US Population is Depressed Yearly

Countless studies show that lack of Vitamin D3 can lead to depression. As the days shrink in the winter season, more people get depressed.

The sun has an uplifting effect. Although the nights are longer during the winter, the cloud cover could block out the sun for days and weeks.

I remember, in a particular February, for two weeks I didn’t see the sun. Everything was grey from morning to evening. Countless people told me that, during these times, they are sleepier and tired.

I remember college when the first spring days appeared. We preferred to sit outside in the sun than go to classes. It felt much better.

Back to the point. If you don’t get enough sun exposure during the summer months, then your D3 storage will be used up faster. This means that you are more susceptible to different Vitamin D deficiencies.

Your mood can suffer as well.

3. Fatigue and Tiredness:

Polls show that 15% of women and 10% of men consider themselves extremely tired

This happens to many people. The time is just after noon, and it’s hard to concentrate and keep your eyes open.

In some high-tech companies, they permit the workforce to take power​-naps. The truth is that these unicorns are a dime a dozen.

So what can normal people do? One option would be to take extra coffee. As the coffee science is inconclusive, you might want to take a pass on it.

One side effect of coffee, as everybody agrees, is that the more you take, the more tolerant you become. So, to achieve the same focus, you need to drink more.

By taking some Vitamin D, you might find that it unlocks a burst of energy.

I’ve been supplementing for years now and still have energy drainage problems. My young daughter usually wakes up between 5 and 6 am, and she doesn’t go down until noon. I already have the necessary D3 levels, so I tried something else.

Nutritional yeast was recommended to me by a doctor. It’s filled with B vitamins. After taking it for a few days, I felt the changes. I managed to get up easier.

For me, it was the lack of Vitamin B1. For somebody else, it might be something totally different.

4. Slow wound healing:

6.5 Million Americans Suffer from Slow Wound Healing

An important sign of the body being deficient in D3 is slow wound healing. Vitamin D3 is known for its antibacterial and inflammation management.

If the body is lacking D3, maybe this is the reason injuries take more time to heal than normal. No matter what kind of injury you suffer, there’s inflammation. This is the body’s natural response. It rushes blood to the injured surface.

The blood contains a lot of beneficial materials to stop infection and start the healing process.

Some smokers experience slow wound healing because of the lack of oxygen in the blood.

There are a number of studies linking D3 deficiency to this problem. If you happen to notice that the body reacts slowly to the healing process, it’s a good idea to look into this issue.

5. Bone loss:

Bone Loss Accelerated with Age More Clearly in Men than in Women

This is mostly present in the elderly. If they are diagnosed with osteoporosis or any form of bone loss, they are advised to take Calcium. The sad truth is this. Most Ca supplements are CaC​O3, more commonly known as lime stone.

If the stomach acid is not strong enough, the Ca is not absorbed. CaCo3, in normal circumstances, is minimal at best. This is why you need to add Vitamin D3 to the mix. It has the power to increase absorption by 25X.

To finish the cycle, you also need Vitamin K2. Once D3 pulls the Ca into the bloodstream, you need K2 to deposit it into the bones.

6. Skin problems:

5.1 Million People Treated Acne in 2013

It is widely accepted that D vitamins have a positive effect on the immune system.

As the immune system gets more sluggish, different things happen in the body. For example, a sign of a weak immune system is poor skin health.

If you have a weak immune system, the skin produces excess oil. This leads to clogged pores. It doesn’t take long to develop acne.

Psoriasis is also a common issue for those whose immune system is not working optimally. 

People who have suffered from these conditions took some Vitamin D3, and the symptoms vanished.

7. Weight issues:

Washington Post: Your chances of losing weight and keeping it off is 5%-10%

It would be great if we could lose weight just by taking Vitamin D. The weight loss process is much more complicated than that.

Studies show that those people who have a higher fat concentration need bigger doses of D3. There are water soluble vitamins, but Vitamin D3 is a fat soluble one. It is stored in the fat cells.

If you have been on a good diet and combined it with an exercise program and you’re still not losing weight, then it’s time to check out D3.

Another known fact about Vitamin D is its beneficial effect on diabetes. Many doctors believe, before full-blown diabetes takes its toll on the body, there’s an insulin resistance phase, called pre-diabetes.

By taking D vitamins, you can fix the issue. Once it’s fixed, then weight loss will happen automatically.

8. Bone and back pain:

Because of Back Pain 264 Million Work Days are Lost Every Year

As you know, Vitamin D3 helps absorb Ca from the stomach. D3 moves Ca into the bloodstream, and with the help of K2, it deposits it into the bones.

If you have bone and back pain, it could be a sign of deficiency. I can easily relate to this.

For a number of years, I’ve been doing martial arts. We focus on a lot of wrist and elbow locks. When I mean locks, I mean pain. There’s a particularly nasty lock that hurt both my wrists.

I was protecting the one that hurt, so the other one got inflamed as well. After taking Vitamin D3 supplements, the pain slowly dissipated and never came back.

9. Excessive hair loss:

Over 80 Million People in the US Suffer from it

Hair loss is normal. Every day, we lose around 50-100 strands of hair. If you notice a bigger loss, then it might be this deficiency.

I know for a fact that stress is a major sign of hair loss. But if you are not under huge pressure and you are losing excessive hair, then it might be some kind of deficiency.

My wife has suffered a lot with hair loss. Once she became pregnant, it all stopped. During her pregnancy, she was so happy that a minimal amount of hair remained in her hand after combing.

After our daughter was born, this process stopped. She started to lose a lot of hair for a few months. I don’t remember how many months passed, but everything returned to normal after her body made the shift.

Adequate levels of Vitamin D may protect you from hair loss.

Let me tell you a secret. There are a number of hair loss products on the market that contain Vitamin D for this reason.

10. Excessive sweating:

ScienceDaily: 7.8 Million People Suffer from it

The body’s natural reaction is to sweat. If you do a good workout, you also sweat a lot. This is how the body regulates temperature.

There are other reasons to sweat. For example, being under pressure makes people sweat. Imagine holding a speech in front of people. Are you sweating already?

Not long ago, I did so. It’s been quite a few years since I made a presentation. It’s natural to sweat in these conditions.

If you are under normal circumstances and you are sweating a lot, it’s time to look at the deficiency.

It’s commonly known that babies who sweat a lot are deficient in Vitamin D3. It’s normal to supplement in these cases.

 Now, these were the most common signs of Vitamin D3 deficiency. Some are general, like tiredness and pain, but if it can be fixed by being out in the sun or taking supplements, I’m all for it.

In the following section, I will be touching on the following topics: anxiety and depression, obesity, and influenza.

I picked these topics because people want to know if Vitamin D can help in these situations. Let’s get to it.

Can you cure anxiety and depression with regular Vitamin D supplementation?

18 Million adults suffer from it every year

​The normal treatment for anxiety and depression is usually strong anti-depressant medication, and electro-shock therapy is having a comeback as well.

There are normal depressive states, like losing a loved one or losing a job. These are traumatic experiences, and this is how the body heals.

Now, depression is loosely defined. There’s a checklist; if you tick more than half of it and it lasts more than two weeks, then you’re most likely in a depressive state.

Besides depression, there’s SAD (seasonal affective disorder). Many people are affected by it. Epidemiologists estimate 3-7% of the US population is affected by this disorder. There was a study that shows 1.5% of people living in Florida are affected by SAD and 10% who live in New Hampshire. There is a strong correlation between the geographical location and how much sun we’re exposed to.

If you are suffering from SAD (in a depressive state from fall to spring), you have two choices to treat yourself. The first one is taking strong anti-depressants (they have some serious side effects). Or you can go with light therapy.

Light therapy has 86% success rate treating SAD

There are numerous FDA approved light boxes on the market that simulate the sun. This is usually advised by doctors.

These light boxes usually emit 10,000 lux, which simulates the sun. Regular office lighting reaches 500-700 lux power. For 80% of patients, light therapy works. Guess what! There are no side effects whatsoever.

Light boxes don’t emit any UV rays, so the skin won’t produce Vitamin D.

Let’s get back to the depression and Vitamin D connection. During the winter months and when there’s less sunlight outside, people are in a bad mood.

There’s a direct connection between Vitamin D and Melatonin. Melatonin is the sleep hormone. Here’s a heads up; never take Vitamin D supplements before sleep. Vitamin D stops melatonin production; thus, you will have poor sleep quality.

Think about it; when the sun is shining, it’s hard to get great sleep. Sun creates Vitamin D in the skin. Here’s the connection between the two.

There are numerous studies that have linked Vitamin D deficiency with depression. People who have a serum level lower than 20 ng/ml are more likely to be prone to depression.

Depression Statistics By State ​​(Interactive Map)

​The ​population ​affected by depression in %

[mapsvg id=”508″]

Besides the melatonin connection, there’s another one between Vitamin D and the feel-good hormones. It has been shown that Vitamin D has a direct effect on the adrenals. Many feel good hormones, like dopamine and epinephrine, are created here.

They are not just about feeling good; they also manage stress and energy levels. As you can see, any malfunction in this system can lead to suboptimal efficiency.

If there’s a lack of Vitamin D in the system, the adrenals work on and on until the body is exhausted. This is how people get into a chronic fatigue state.

Inflammation in the gut and the brain leads to anxiety and depression. Another correlation was noticed amongst patients with depression; they all had lower bone mass.

This means there’s not enough Vitamin D in the system to put calcium into the bones. If it can’t even do that, then other functions are impaired as well.

Doctors suggest that, in these cases, the Vitamin D levels should be measured. If they are low, supplementation could help with both anxiety and depression.

The anti-depressants are always there if you need them. If it was me, first I would try something that doesn’t have side effects.

All those diet plans failed, maybe Vitamin D can stop Obesity?

1 in 3 adults were considered to be overweight

Have you noticed the media is constantly cranking out newer and better diet plans? They all promise instant weight loss and super easy results.

If that’s so, why is the obesity rate constantly rising?

By sheer dumb luck, one of those diets should work…

The human body doesn’t change overnight, so it means something else is to blame. To set the record straight, obesity doesn’t kill, but the underlying conditions do. The real killers are: type 2 diabetes, heart disease, stroke, kidney failure, and cancer.

So how does Vitamin D come into play?

When we eat something, insulin is triggered to drive glucose into the cell from the bloodstream. And when insulin levels are high, it triggers the release of leptin that tells the brain that you are full and stop eating. This happens in normally.

​When there’s an insulin insensitivity, it forces the pancreas to put out more insulin to keep blood glucose levels normal. Insulin causes fat deposition that leads to obesity.

Unfortunately, obese people become resistant to the appetite suppressing properties of leptin and this means that it takes more eating to trigger the “I’m full effect”. This leads to over eating.

This is where Vitamin D lends a hand. If a person has adequate amounts of D3 in their blood, the insulin is triggered faster. Also, it increases the insulin sensitivity meaning you will feel fuller faster. Thus, there is a reduction in overeating.

There’s also another point of view from Dr. Holick. Our body is smart and it knows that winter is coming. So it stores Vitamin D3 in fat cells for later use. This is the normal process.

You would assume that the more fat cells one has, the more D3 would be available as well. That might be true, but it’s locked away. It’s like me saying to you here’s $1,000,000; it’s all yours do what you wish … oh wait it’s on the International Space station.

For D3 to be useful in the body, it has to be available in the blood. If you have a moderate amount of fat, then eventually, those cells will be burned up and Vitamin D released in the blood stream.

In the case of obese people, all that D3 is locked away, waiting to be used someday. I believe Zig Ziglar said this best: “I checked every day of the week, and there’s no Someday.” That day never comes.

For this reason, obese people need to take 2 to 3 times more Vitamin D according to Dr. Holick. His team and others have done some tests.

Two groups of people, one obese, one normal, were put into tanning beds for the same amount of time and have shown that obese people have only 50% of Vitamin D in their blood.

To eliminate body surface issues, they have repeated the test with an injection of 50,000 International Units of D2. The results were the same. The experiment has been repeated with the same results.

To feed the downward spiral, many obese people avoid the outdoors, so they don’t get enough sun exposure. This will lead to an even lower level of Vitamin D.  This makes everything else worse.

​Obesity Statistics by State (Interactive Map)

​The population obesity rate in %

[mapsvg id=”471″]

To sum everything up, there’s a cause and effect between obesity and Vitamin D levels. If one is obese, then Vitamin D levels are low. Also, low Vitamin D levels lead to obesity.

Here are Vitamin D deficiency signs relating to metabolism:

  • ​Fat is stored around the waist, instead of being burned, and muscle mass is decreased.
  • ​Stress hormone levels are decreased, which will lead to increased blood pressure.
  • ​Inflammation around the body will appear, which damages blood vessels.
  • ​Less insulin is secreted.

Is Vitamin D the influenza, cold buster?

5-20% of people catch the flu every year

Before we can answer that question, let’s look into the flu or influenza. What is the flu and how do you catch it?

The flu is a harmful virus that enters the human body and does one thing: reproduce. If the immune system is at its A game, then we usually don’t notice anything. On the other hand, if it’s sluggish, then we are bedridden for a number of days.

Here’s a very important lesson I’ve learned from Dr. John Bergman. Viruses are not alive, and they can’t be killed. Viruses have two stages, active and in​active.

If you have contracted a virus and healed yourself from it, I have some bad news. The virus is still there waiting for your immune system to weaken.

Here’s the good news; if you have a strong immune system, then the viruses will stay dormant.

When a virus enters a body where the immune system is weak, it starts reproducing fast. By entering a host, the virus changes its DNA. This is why we can’t get immunity from it. The flu virus is constantly mutating as it moves from one host to another.

Think about this mutation the following way. Let’s say we are familiar with an X shaped pattern. Every time we see that X shape, we know it’s bad. Here’s the genius part of a virus; it changes. So, we see the X, and maybe the next day, it will mutate to a Y or some other shape.

We’re not familiar with that, so we might get infected until we learn that Y isn’t friendly either. This is the cycle of the flu. Here’s the reality; anybody can play catch up, but it will never get ahead of the virus because it’s too random.

Think about the HIV virus. It compromises the immune system to the state that an average cold or infection kills the host. HIV virus doesn’t kill in the short run, but in the long run, it leaves the body defenseless against other pathogens.

Influenza/Pneumonia Mortality by State in 2017 (Interactive Map)

[mapsvg id=”590″]

Doctors observed the following thing. The majority of flu cases appear during the winter months. This is when there is less sunlight outside, plus there’s no UVB radiation to create Vitamin D.

The flu usually hits in January or February because this is when the D3 reserves are the lowest. The observation holds merit.

From my own experience, since I started supplementing with Vitamin D, I wasn’t affected by any cold or flu.

There’s another school of thought as well. Since it is winter, we stay indoors more than usual. We don’t ventilate the rooms as much. This leads to stuffy air filled with bacteria just waiting to pounce on us.

I might’ve believed it before, but now it’s different. There were years in a row that I got sick, and as I started taking supplements, it all stopped. My longest stretch was ​5 years without any symptoms.

Now, what happens when your immune system is weak and you get the flu?

I remember a particular sickness of mind. It was strange. I lost the sense of taste for a few days. 

Let’s look at the body’s perspective. The healing process demands a lot of energy. So, for the body to be efficient at it, certain processes are minimized.

For example, when I’m sick, I lose my appetite. Eating is an energy consuming activity. The body needs all the energy it can get to heal. This is why we sleep so much when we’re feeling under the weather.

It’s perfectly okay and fine not to eat. The body has enough reserves to last for at least 7 days. This sort of explains my loss of taste. I was in such bad shape that my body needed more time and energy to heal.

I remember that my parents made me special chicken soup, and after just one spoon, I said that I can’t taste anything. It’s just bland. I went back to my bed and slept some more.

This is the flu cycle. As I’m writing this, there’s a particularly strong flu going on. School has been canceled for a few days, and over ​124 people have died. I do everything in my power to have a strong immune system.

No comment…

My good friend’s smallest daughter contracted the flu a few days ago. High fever and muscle pain.

It’s hard to look at your toddler child in pain.

They went through 5 days of hell. After that, her small body rebooted, and everything returned to normal.

My friend checked out the government’s website about flu info. This strain of the virus has a 1-4 day incubation period and 3-5 days sickness. If you have taken the flu shot, then it might be less than 5 days.

​This isn’t encouraging if you are on the fence of getting the flu shot. As far as I know, it’s too late to take the flu shot in January or February.

Is Vitamin D better than the flu shot?

I can’t say because I never vaccinated myself against it. If you look at the statement on the governmental website, it’s like Russian roulette. It might help you; it might not. It does not say that you are immune, by the way.

Back to our original topic.

Can you avoid the flu by taking D3 supplements?

From my personal experience, the answer is yes. I’ve experimented on myself and on my family. Plus, there are countless studies backing up the claim.

During and after the First World War, there was the Spanish flu. Researchers say the flu killed more people than the whole war. Also, studies show that you were more likely to survive if you lived in Texas than in the Northeast. It’s a scary thought.

All in all, having a strong immune system helps. Whether it be flu or colds, it gives you a better life. Countless agencies are advocating having a serum level of 20 ng/ml or 50nmol/L. The higher you have it, the less disease you will contract.

What’s the optimal range for Vitamin D3?

​The simple answer is this: NOBODY knows.

Everybody has a different number in mind.

Before I get to that, let me show you the following chart. Vitamin D3 is measured in the blood. In the lab, they are looking for 25-Hydroxy Vitamin D. Because we live on a huge planet, the results are lab dependent. Some labs give the results in ng/ml, and some give it in nmol/L.

The conversion isn’t that easy either.

​To make conversions easy here’s a simple calculator to do the math.

Convert ng/ml to nmol/L (calculator)

[ezfc id=’5′ /]

Convert nmol/​L to ng/m​l (calculator)

[ezfc id=’6′ /]

​So, if people can’t agree on a standard measurement, it becomes even harder to decide on the optimal level.

25(OH)D Blood levels

Vitamin D Status



Severely Deficient















High, but not toxic



Toxicity possible

above 100

above 250

Vitamin D3 RDA Vs Optimal level

RDA is established so below that level, the body is severely deficient, and many health problems start to occur.

Take for example Vitamin C. The RDA for Vitamin C is 60mg/ day. This is the benchmark for scurvy. If you have less Vitamin C, you develop scurvy. Is being above the scurvy line enough?

Or if you want another metaphor, is drinking just enough water not to be thirsty enough?

What about all the waste that the body needs to wash out?

You need more water for that.

The same thing goes with the RDA. You can easily go over the RDA amount to achieve optimum health.

From now on, when I talk about Vitamin status, I will be using the ng/ml measurement.

According to this chart, the optimum range for 25(OH)D is between 50 and 65. According to GrassrootHealth, it’s 40-70.

Looking at the above 100 toxicity possibility makes me giggle.

As the years go by, the science advances, and the data shows new evidence. Here’s a perfect example:

The first picture shows a chart taken 5 years earlier than the second. The initial theory was that, above 50 ng/ml, death rate increases.

And in the updated study, from 50 to 75, there’s a sharp decrease in deaths. Live and learn.  There’s no proof that you will die early if you have higher levels of Vitamin D in your blood.

Yes, there’s possibility of toxicity. There’s always possibility of toxicity at any level.

Here’s another chart to look at.

It clearly shows that you are safe under the 200 ng/ml mark. There were no toxicity reports below that. Later, I will analyze this chart a bit more in detail.

As I mentioned, everybody is guessing. Some are betting on the low side, some on the high side.

According to Dr. Holick, the Hadza tribe in Africa has the highest levels of D3 in their blood. Just in case you were wondering, they are not supplementing. Being in the Serengeti, they get a lot of sun exposure.

Their D3 levels on average are at 115 ng/ml. They are way below the 200 mark. From all this research, we can conclude that the higher the blood serum level, the better. 50-65 is ok, but you can safely increase it to even higher levels.

What’s the optimal range for Vitamin D3?

Vitamin D supplementation increases health benefits

If you’re not living close to the Equator, you most likely have to. If you are living up north, then it’s a must for optimal health.

There are people who are supplementing only during the winter. Don’t forget Vitamin D isn’t water soluble; it is fat soluble. When it’s created, it is stored in the fat cells.

If you get healthy exposure during the summer months, you will have ample Vitamin D during winter. There are countless studies showing that flu season usually hits around January or February.

Most people are living off their D3 stores from September through December. Once the reserves are used up, the immune system starts to suffer, leaving the body exposed to diseases.

This observation correlates with people who live on the south part of the world. When it’s summer on the northern hemisphere, it’s winter down south.

There are more flu cases reported during these months. Most people call it winter, but certain doctors call it low Vitamin D months.

But what about regions where there’s no winter?

The data shows that, during monsoon season, which is low Vitamin D season, again, there is an increase of disease.

All in all, it’s a good idea to supplement. If you are out in the sun during the summer, it might be great to supplement only during the winter months.

One of the most common questions that I get is this:

How much Vitamin D3 should I take? 

Should I take it daily or weekly or monthly?

If you thought the adequate levels were confusing and nobody managed to agree on anything, wait until you see the supplement dosage.

Every society and medical agency has their own opinion. The only form of agreement between them is that they don’t agree.

Let me show you this. Here are three institutes with 3 different recommendations for daily intake.


600 IU

​Endo. Soc.

1,500-2,000 IU

​Am. Ger. Soc.

4,000 IU

Now, the RDA is 600 IU; recently, it has been increased from 200 IU. This shows the importance of Vitamin D3.

So, which one should I follow, and what does IU mean, anyways?

First, we had to digest ng/ml and nmol/L;  now we have IU. Don’t be scared. I will break it down for you. IU means International Units.

For Vitamin D2 and D3, IU equals 0.025mcg (micro grams). 1 microgram is 1/1,000 of a gram. Because the amount is so small, they opted for IU for easier use.

  • 100 IU /day in the following months will increase your Vitamin D blood levels by 1 ng/ml (2.5 nmol/L).
  • 1,000 IU /day will increase your Vitamin D blood levels by 10 ng/ml (25 nmol/L).
  • ​4,000 IU/day will lead to 40 ng/ml (100 nmol/L).

Here’s a quick and easy calculator to estimate how much your serum level will increase in 2-3 months.

​​Vitamin D Level Increase by IU Intake (calculator)

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This is how you can measure the amount you need to take. First, you need to know your blood level to get an accurate picture. After this, you can use the following formula:

If you are taking Vitamin D for 2-3 months, your 25(OH) will increase.

Studies show that Caucasians have a 25(OH) level of 25-27 ng/ml. For African Americans, it is 15-17 ng/ml.

For simplicity, let’s say your levels are 25 ng/ml, and if you are taking 1000IU a day, in a couple of months, your levels will reach 35 ng/ml.

I know it’s complicated. This is why I’ve tried to simplify it as much as possible.

There’s a simple way to calculate a basic dose as well. This relies on your body weight.

IU = Weight (pounds) X 27


Body Mass


Daily Vitamin D (IU)

200 pound adult

200 x 27


100 pound teenager

100 x 27


50 pound child

50 x 27


​Handy Calculator to Measure IU by Your Weight (calculator)

[ezfc id=’1′ /]

Here are two solutions for you to calculate how much Vitamin D3 you should take.

This is my dosage. I don’t take any responsibility if you follow my advice. I usually take 8000 IU a day. My routine is as follows. 5 days of 8000 IU and I skip it during the weekends.

Most people are deficient in Vitamin D. So, it’s a good idea to supplement.

If it’s winter, you already know there’s no UVB, so you can’t make your sunshine vitamin. Plus, you can’t expose too much skin either.

During winter, you have the following options to get the right dose: foods, supplements, and lamps.

Let’s talk about foods first.

Here’s the top list of food that contains Vitamin D.

1: Cod Liver Oil – 1 tablespoon contains 1,360 IU.

Cod Liver Oil contains 1,360 IU

Do you have traumatic experiences from childhood about cod liver oil? Most of us do. I get it that it’s healthy, but there’s something to be done about taste. If you can stomach one full tablespoon, go for it.

For my IU levels, I would have to swallow at least 7 tablespoons every day. I wouldn’t last a week.

2: Salmon – 1 serving, usually 3 ounces, contains 447 IU

Salmon contains 447 IU

You need to make sure the salmon is wild caught because only these fish have this high amount of Vitamin D.

Sadly, farm raised ones have only a fraction of it.

Stick with wild caught for the most amounts.

3: Tuna – 1 serving, usually 3.5 ounces, contains 236 IU.

Tuna contains 236 IU

In most cases, people opt for the canned version. It’s easy to store, and there’s isn’t any hassle with cleaning in the case of live one.

Most sea creatures contain mercury, which is highly toxic for the human body. The bigger the fish, the more mercury it contains. Smaller fish are safer.

4: Oysters – 1 serving, usually 3.5 ounces, contains 320 IU.

Oysters contain 320 IU

Oysters are native to salt water. Besides Vitamin D, they contain a lot of minerals. By having oysters regularly, you can beat multivitamins with ease.

For example, you can get Vitamin B12, zinc and copper. The bio-availability of these vitamins and minerals are much higher than any multivitamin you can buy.

5: Eggs – 1 egg contains 20 IU.

Eggs contain 20 IU

The D vitamin is contained in the egg yolk. There are some people who prefer the egg whites, and they are missing out on the best part.

In concentrated feeding operations, Vitamin D levels are lower than free range pasture raised chicken eggs.

While doing my research, I’ve found that, if the chickens get enough sun and are fed Vitamin D rich food, the IU is much higher. A source says that it can reach 6,000 IU.

I heard about doping and steroids, but this is ridiculous. Obtaining 300X gains is just unheard of.

6: Fortified Milk – 1 cup contains 120 IU.

Milk contains 120 IU

Cow’s milk is a great source for minerals and Vitamin D.

Again, free range cows contain much more IU than farm raised ones.

In certain countries, the milk is fortified to beef up the vitamin content.

7: Mushrooms – 1 serving of wild mushrooms, usually 3.5 ounces, contains 2,300 IU

Mushrooms contain 2,300 IU

Commercially grown mushrooms contain less than 10 IU.

Mushrooms have the ability to synthesize Vitamin D when they are exposed to UV light. Animals and humans create Vitamin D3, and plants create Vitamin D2.

The difference between D2 and D3 will be detailed a bit later.

Commercially raised mushrooms are grown in the dark, so that’s the reason their IU levels are so low.

Here’s a great story I read while researching the subject.

In the UK, a patient goes to the doctor, and they find out he is suffering from Vitamin D deficiency. The person goes to the electric store and buys a UV light and then hits the grocery store for some mushrooms.

Before he ate the mushrooms, he exposed them to UV light. After a few months, he cured his deficiency. His Vitamin D levels reached a normal range.

Talk about a DIY approach that works.

This covers the most important food sources that can complement your diet.

Here’s the thing that nobody talks about. You either need to eat a lot or eat something that you don’t really like just to reach the RDA.

Imagine swallowing all that cod liver oil day by day or eating 30-40 eggs just to reach 600-800 IU. Do you fancy oysters? I hope you have a heavy wallet. You can rely on milk 6 cups to get you to the minimum daily amount.

Even if you change up the foods every day, it’s a lot to eat.

What if you need 6,000 or 10,000 IU a day?

It’s impossible to eat that much.

This is why the supplement industry is booming. It’s much easier to swallow a pill than eat 30 eggs.

Ok, which one should I take? 

There are so many of them.

What about Vitamin D2?

By now, you know a ballpark figure on how much Vitamin D3 you should take. In this section, I will tell you all about the different option you can take. And later, I will show you the difference between D2 and D3.

​What​’s the best supplement to combat deficiency?

Too much sugar for my taste

Here are the top ways to take Vitamin D: pills, drops, gel caps, and chewables.

Most chewable tablets contain sugar. If you are chewing on it, the taste has to be good. So, sugar is added. I personally try to limit my sugar intake, so I’m not a fan of it.

Most chewable tablets are made for kids. My views on this differ here as well. I didn’t dig into any kind of research because it’s not interesting for me.

Now, according to Carole Baggerly, head of GrassRootHealth, all other forms of Vitamin D supplements are good. The absorption rate is the same.

Drops are the preferred way to administer it to babies.

Since my daughter has just grown out of the baby phase, I still remember how hard it was to give it to her daily.

This is not Reality!

It was before she learned to roll or move around.

Of course, a couple of drops always landed on her face. And when her mouth was wide open, the drops didn’t want to come.

After this period, there was a more restful one. She accepted the drops and pointed her little tongue out because she loved it.

Now, we’re back at the wrestling phase.

Pills and gel caps are just as good. I prefer gel caps because they’re easier to swallow.

For some reason, no matter what kind of pill I take and with how much water, it gets stuck in my throat. I have never had problems with gel caps.

This is my personal opinion: Since Vitamin D is fat soluble, the gel caps contain some kind of fat; maybe it helps absorption?

​When should I take Vitamin D?

According to Dr. Alan Mandel, there are two recommendations. First, always take it with a meal and not on an empty stomach.

Since it’s a fat soluble vitamin, adding fat to your meal should help absorption. There are different studies that just lead to confusion. Some show that having it with a meal is better; some show that adding Ca to it helps absorption. I couldn’t make heads or tails of it.

This is when I usually listen to my gut. I usually take it with my biggest meal, which is around noon.

Dr. Alan Mandel’s observation should be taken into account. Vitamin D has an effect on melatonin. This hormone regulates the sleep cycle.

It’s not wise to do Vitamin D supplementation before going to bed or with dinner. It will inhibit melatonin production, and your sleep might get affected.

I’ve just learned this not long ago. It’s a good rule of thumb to keep in mind.

Is there a difference between synthetic and natural D3?

The synthetic version of D3 is as potent as the natural one that is created from cholesterol through UVB radiation. Yet, the body is smart and detects the differences.

There’s only a slight difference between the two. The synthetic version’s half-life is somewhat shorter. The natural version is a bit more stable than its counterpart.

This is the only difference between the two.

Can you increase your D3 levels with a Vitamin D Lamp?

Special UVB radiation will trigger Vitamin D3 production

As I mentioned with the example of irradiating mushrooms by ultraviolet bulbs, it’s possible.

There are a number of different solutions if you want to go down this route. I personally haven’t tested or researched any of them. What follows is a brief overview. Maybe in the future, I will expand on this.

If you hit up Amazon, a number of different products appear. They are called sun lamps. Yet, they don’t mention anything about D3 or UVB. This is what you need if you want your body to create Vitamin D.

Another option is home or professional tanning options. All I know about this is every studio and every bed are different. Some use UVA UVB UVC (you don’t want to get UVC in any form). UVA is highly used because that tans the skin fast. But UVA is also linked to skin cancer. I wouldn’t choose this option.

If I was forced to use a Vitamin D lamp, then it would be something like this: Narrowband UVB. Brace yourself; this isn’t cheap. There are a few companies that created tanning salon style walk-in Vitamin D beds. Last time I checked, they are in the $2000-$3000 range.

Maybe in the near future, I will try one and tell you about my experience.

Should I take D2 or D3? What’s the difference between the two vitamins?

Vitamin D2 aka Ergocalciferol

There are two variations of Vitamin D. One is D2, and the second one is D3.

This is what you need to know about them.

Plants create D2 when they are exposed to UVB, and mammals create D3.

The human body can utilize both of them. If you take D2 or foods that contain D2 (like mushrooms), the body has to do a conversion from D2 to D3.

As you have assumed, there’s no congruency here either. Dr. Robert Heaney says there’s no difference between D2 and D3. He uses D2 in his practice.

Now, according to Dr. James Dowd, the difference is huge. D2 is 30% of D3 efficiency. This means that, if you are supplementing with D2, then you need to take more.

The human body is used to making D3, so it would be normal to assume that it can’t convert 100% of the D2 into D3.

Vitamin D3 half-life, how much time it takes to metabolize half of it, is 10 weeks. For D2, it’s 7 days, and it’s completely eliminated from the system in two weeks. Compare this to Vitamin C; it has a half-life of a few hours.

It seems that D3 is stronger and lasts a lot longer. The evidence is mounting against D2.

​Who ​should supplement with D2?

Vegans and vegetarians are great fans of D2 because it’s made from vegetables.

The truth is these supplements are created synthetically. There are no animals involved in the process, so it’s safe to take.

Also, Dr. James Dowd considers that the cost of taking D2 is much higher than D3. To get a year’s worth of supply of D3, it would cost you around $20.

If you plan to take D2, then you would pay 8-10 times more for its 3-4 times less effective counterpart (based on weekly dosing).               

​​Can you overdose using Vitamin D3? What are Toxicity symptoms?

As you learned above, there is no golden rule on how much Vitamin D you should take. If you are taking the RDA as a reference number, then you would be overdosing in a matter of minutes if you are close to the Equator.

According to Dr. Holick, Dr. Dowd, and Carole Baggerly, in normal circumstances, the amount you overdose with has no negative effect on the body.

Dr. Holick routinely treats patients with 50,000 IU a week without any side effects. It’s one of the safest vitamins out there.

The body is smart; it will stop generating D3 if it has reached the threshold.

Just think about this.

You are staying out in the sun. Eventually, you will get sunburned.

This has happened to me while on vacation. Sadly, I never learn. I get sunburned extremely fast. I didn’t put on any protection, and I got burned.

The next day, I was in pain. It was so painful that I couldn’t bear the sun. So, I stayed inside for a couple of days. This is what I call hard mode. Sure, I got a lot of D3 on the first day. But for 2-3 days, I wasn’t out in direct sunlight. I adopted the vampire routine.

There are signs that UVA after a certain amount starts to destroy D3. That’s another safety measure to protect the body from harmful effects.

​​Can you overdose on supplements?

In case of food, you have already seen that it will take incredible effort just to reach a few thousand IU.

With pills and gel caps, it is extremely easy to reach 10,000 IU.

Earlier, I showed you this chart:

Now you know exactly how to interpret the chart. Earlier, I didn’t want to go into details. If you don’t understand ng/ml, nmol/L and IU, you wouldn’t get it.

The vertical axis shows blood serum levels in nmol/L. The horizontal axis shows the amount if D3 people were taking in IU. Yes, you have seen it right; the maximum number on the chart is 10 Million.

Somebody experimented with 5 or even 7 Million IU a day. And some doctors are freaked out at 4,000 IU.

The lower left quadrant is the safe zone. This means there were no adverse effects under 30,000 IU and blood serum level of 200 ng/ml. Remember the Hadza tribe from Africa? Their average serum level was 115 ng/ml.

As mentioned, it’s a very safe vitamin. There is a wide range before any toxicity appears.

The Mayo Clinic conducted a study as well. There were 20,000 participants, and they all were taking 50,000 IU a day with Ca. They were followed for months, and only 1 case of toxicity appeared. 1 in 20,000 is great.

For full disclosure, there are certain side effects for people with rare genetic diseases.

Vitamin D toxicity is proved when the serum level is high (this wasn’t pinpointed in any research paper) and the patient has high Ca in the blood.

The problem with this comes from Ca getting deposited in the arteries, and this can lead to heart problems. If you take K2, you can rest assured Ca will be deposited in the bones.

​Symptoms / side effects of Vitamin D toxicity

  • Frequent urination
  • Nausea
  • ​Vomiting
  • Poor appetite
  • ​Constipation
  • ​Weakness
  • Weight loss

Taking high doses of Vitamin D with high doses of Ca can lead to kidney stones, according to Dr. Dowd. Other researcher say that kidney stones can’t be linked to Vitamin D.

High levels of Ca in the blood need to be stored somewhere, so the body deposits it in the skin, muscles, and internal organs.

Dr. Holick and his colleagues agree on the following. It’s extremely rare to have Vitamin D toxicity. It’s the safest vitamin to take.

Thank you for reaching the end. This concludes my article about Vitamin D. Below you can see the cliff note version and the references.

​Medically Reviewed by:​Kimberly Langdon Cull M.D. OB/GYN USA


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Treatment of Vitamin D Insufficiency in Postmenopausal … – NCBI – NIH
Treatment of Vitamin D Insufficiency in Postmenopausal Women: A …
Vitamin D and the skin: Focus on a complex relationship … – NCBI – NIH
vitamin d: a d-lightful solution for health – NCBI – NIH
slow wound healing
bone loss
skin problems
weight issues
back pain The Hidden Impact of Musculoskeletal Disorders on Americans, United State Bone and Joint Initiative, 2018.
excessive hair loss
excessive sweating
Alan L. Rubin, MD ​Vitamin D for Dummies
James Dowd, Diane Stafford The Vitamin D Cure
Michael F. Holick Ph.D.  M.D.,  Andrew Weil The Vitamin D Solution
Mayo Clinic Study
Michael Holick – The D-Lightful Vitamin D for Good Health
Vitamin D Sunshine Optimal Health: Putting it all Together
Vitamin D & Cancer  current trials and evidence Carole Baggerly
Dr. Robert Heaney Speaks on Vitamin D in Calgary
The Vitamin D Cure With Dr James Dowd
Obesity Map
Depression Map
Influenza/Pneumonia Map