Everything you need to know about Vitamin D

Last updated:
Join us and over 84,000 people
Our Paleo Guide: Your Guide to Paleo

You’ve probably heard about the importance of having good levels of Vitamin D, but you might be wondering why there is so much talk around this particular vitamin, especially in the Paleo diet circles.

One of the reasons Paleo eaters put so much importance on Vitamin D is because it’s one of the only vitamins you could still be lacking, even on a balanced Paleo diet.

The reason behind that is not that a Paleo diet misses anything, but because the main source of Vitamin D is sunlight.

In fact, if you work inside or live in a northern climate, chances are you are already deficient in this primordial constituent of our health.

Vitamin D is produced by cholesterol in the skin when in contact with UVB sunlight. You can see, then, that cholesterol is a very important constituent of a healthy life and those taking statins to reduce their cholesterol are at even greater risk of Vitamin D deficiency.

It’s important to understand that cholesterol is not bad per se and is a vital hormone produced by our bodies. When we consume foods high in cholesterol our body down-regulates its own production so we don’t get too much of it. What’s bad about cholesterol is too much small dense LDL cholesterol particles in the blood, which is often caused by inflammation from too much carbohydrate, insulin resistance and Omega-6/Omega-3 imbalances.

The SunComing back to Vitamin D, you have to understand that sunscreen blocks all the UVB light from entering the skin and thus causes no Vitamin D to be produced. Again we get to see that, to be perfectly healthy, following our ancestor’s footsteps is a good idea. Our bodies have evolved for millions of years under those conditions so it’s no wonder that drastic changes affect us.

Of course we don’t recommend you get out of your home after months of hiding from the sun and start gazing under it four hours right away.You’ll get a major sunburn if you do that, and you already know that this is in no way healthy.

Our bodies have a natural mechanism to protect us from too much sun exposure: natural tan. In fact, Vitamin D is in direct competition for absorption with folate (or Vitamin B9), another vital constituent of our health. Our skin gets darker in presence of sunlight to reduce our absorption of Vitamin D and prevent folate deficiency.

Inuits, who don’t get that much sun exposure, still have a darker skin because they get plenty of Vitamin D in one of the only food sources of it: fatty fish. It’s the fat in the fish that contains all the Vitamin D. When our ancestors moved north hundreds of thousands of years ago we started to get less sunlight exposure and our skin became lighter to compensate. That makes white and black skin pretty much only a matter of Vitamin D absorption. Therefore, black people living in northern climates are at even greater risk of Vitamin D deficiency.

Vitamin D is responsible for a lot of different processes including bone health, calcium and phosphate concentration, reducing inflammation and regulating the proliferation and differentiation of cells. A deficiency in Vitamin D can lead to bone problems. rickets in children, osteoporosis and autoimmune problems.

The recommended daily intake of Vitamin D for people between ages 13 and 50 is 200 IU (International Units) and 400 IU for older people. It has been demonstrated however that this recommendation is much lower then the actual appropriate intake. The tolerable upper intake levels have been set to 2000 IU per day in Canada and the US, but evidence shows that doses up to 10,000 IU are perfectly healthy. Read this article for some facts about a study that debunks the current Vitamin D toxicity myth. On the bright side, when you get your Vitamin D directly from sunlight, there are mechanisms that protect you from getting too much.

If you decide to go with a supplement, you should be comfortable choosing one that contains from 2,000 IU to 5,000 IU. Someone living in a tropical area and who is exposed to sunlight all day long could get as much as 12,000 IU a day just from the sun. Remember that those recommending only 200 IU per day are the same people who recommend so much whole grains and carbohydrates, polyunsaturated rich vegetable oils and a low fat intake. Not really a good guideline to follow if you ask us!

If you choose to go with a supplement, choose a Vitamin D3 supplement (the more bio-available form) and try to choose one that comes in a gel capsule since Vitamin D is a fat soluble Vitamin and the body needs fat to absorb it (yet another reason to get enough fat in your diet). A good quality Vitamin D supplement is also part of Mark Sisson‘s Primal Essentials Kit, which is a really good product that we recommend which also contains important omega-3 fats and probiotics.

Finally, don’t forget to have fun under the sun frequently and to eat regular portions of wild salmon or other fatty fish and you should get plenty of healthy Vitamin D.

P.S. Take a look at our Paleo Recipe Book. It's a Cookbook we've created to help you prepare the best Paleo food. It contains 370+ recipes and covers everything you'll need.

+ Your Guide to Paleo, our visual Paleo Guide, was just released. It'll help you avoid the most common pitfalls and reach your health and weight loss goals faster.

Get your free recipes