What’s the Deal with Vitamin D? Is the hype real?

As physicians we are often asked to help clear the confusion about certain media items. Especially during the time of the pandemic there has been a lot of discussion about certain vitamins and their role in health, but none more than Vitamin D. Those who have read our book, The Vitamin Solution: Two Doctors Clear the Confusion About Vitamins and Your Health or followed our blog know that we have been harping about the benefits of vitamin D for years.  If anything, the pandemic has only seemed to confirm many aspects of this important vitamin that we suspected to be true.

We have become aware in recent years that most Americans are in fact deficient in Vitamin D if they do not take a supplement. The degree to which one is deficient of varies depending where you live and other individual features such as skin tone, body weight and medical issues. But why does this matter?

First off, we must point out that vitamin D is actually not your typical vitamin. It is in fact it is perhaps misnamed as a vitamin, it is actually a hormone. Vitamin D is obtained from few food sources (namely liver and there is minor amounts in mushrooms and milk).  Vitamin D is obtained from sunlight but this requires extensive sun exposure with bare skin without sunscreen. Once vitamin D is in our body it is converted to its most active forms by our liver and kidneys. Vitamin D is a fat soluble vitamin, so unlike some others, it is both slow to build up in your body but also slow to leave once stored. This is why the dosing of vitamin D is both complicated and so very important.

So what exactly does this complicated vitamin/hormone do for us? It turns out that its unique status gives it special importance in our bodies. There are vitamin D receptors throughout our bodies.  We originally became aware of vitamin D’s importance because of its role in bone health. Vitamin D receptors in the GI tract help our body absorb needed calcium that then helps strengthen our bones. We have solid evidence that vitamin D deficiency contributes to osteoporosis, making it essential to get vitamin D that allows our body to absorb the calcium which prevents fractures.

There is now more and more evidence that Vitamin D is also essential to proper muscle function. We know that vitamin D deficiency is associated with fatigue and muscle aches. It turns out that vitamin D levels may correlated with muscle strength and athletic performance. Suddenly vitamin D is not just your grandmother’s vitamin (actually, lots of grandmothers are also quite athletic these days!).

So why is everyone talking about Vitamin D these days? As COVID became a major health concern, a new array of data came out to suggest that Vitamin D may play a role in the severity of COVID infection. Since that time several compelling retrospective studies have shown that there is an association between low vitamin D levels and severe COVID infection. While this is by no means absolute proof that taking vitamin D prevents COVID, it does confirm our previous suspicions about Vitamin D’s role in immunity. We know that white blood cells (which fight infection and also contribute to the overactive immune responses seen in severe COVID) have receptors for vitamin D.  The available evidence suggests that Vitamin D helps maintain a healthy immune system and that it not only helps protect us from getting sick but it helps with our body’s ability to regulate our immune response. This is why it may be important in COVID.  People who get really sick from COVID most often have an exaggerated immune response to the virus. Thus, adequate vitamin D levels may help prevent this exaggerated response. Likewise, we have good data to suggest Vitamin D may also play a role in preventing autoimmune diseases such as multiple sclerosis, psoriasis, certain kinds of arthritis and more.

Vitamin D may play other roles and research is coming out constantly suggesting roles in preventing certain cancers, blood clots, diabetes and maintaining memory and heart health.  In short, Vitamin D is worth all of the hype. But what does that mean when we each try to determine if we should take Vitamin D and if so, how much? Well this is where it gets a little complicated. You will hear all sorts of things about how much vitamin D to take. Recommended amounts range from 400 IU to 10000 IU daily.  However, there is huge variation in this and we strongly caution people from thinking that taking more is necessarily helpful Too much of a good thing is not always better and in this case, can be quite harmful. Taking excess vitamin D, because it is fat soluble and can accumulate and cause great harm. It can lead to high calcium levels, cause nausea, vomiting, kidney stones and in severe cases lead to coma. In terms of mortality studies show that blood levels of Vitamin D up to 50 show correlate with longer lives while those over 50 have a higher mortality. In our opinion, an optimal blood level of vitamin D is between 40 and 50ng/ml. Find out more about testing blood levels of vitamins here.

So how should one obtain this optimal level of Vitamin D in order to receive its many health benefits? The answer is not the same for everyone. We all have individual needs for vitamin D (as for every vitamin) depending on who we are, our diet, lifestyle and health concerns. The best way to obtain the proper dose of vitamin D to meet your unique nutritional needs is via a personalized vitamin.  Taking vitamin D can be an essential part of improving and maintaining your health for so many reasons. Take our vitamin quiz to get your optimal daily blend of vitamins.