Vitamin D: The sunshine vitamin

​Not long ago vitamin D was simply known as the bone vitamin because its main function was to help absorb calcium, the most abundant mineral in the body. Since vitamin D was primarily regarded as an important nutrient for bone health, it was conventionally thought that a person had enough vitamin D as long as they didn't have bone diseases like rickets or osteomalacia. However, thanks to the work of many scientists, data now show that vitamin D is much more that just a bone vitamin. It is considered by many to be both a nutrient and a pro-hormone, a compound that the body can convert to an active hormone. In the case of vitamin D, the pro-hormone form is produced in the skin and activated in the liver and kidneys; then the active hormone communicates with a variety of other tissues in the body. Nearly every tissue and cell in the body has receptors for vitamin D. Vitamin D is needed for bone growth and bone remodeling, but also has other roles in the body, including modulation of cell growth, neuromuscular and immune function, and reduction of inflammation. It is estimated that upwards of 2,000 genes are directly or indirectly regulated by vitamin D. 

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Three-quarters of teens and adults in the United States are deficient in vitamin D. The results of this deficiency are catastrophic. Studies have shown that vitamin D deficiency is associated with an increased risk of a long list of diseases that span all systems in the body. As a woman, I am particularly concerned with the link between vitamin D deficiency and breast cancer.

​Michael Holick, a biochemist and endocrinologist at Boston University, is a pioneer in vitamin D research and believes that the role of vitamin D in the body is so profound that much higher doses than those currently recommended are required for optimal functioning. While humans can make vitamin D in their bodies, most of us require additional amounts from the sun, our diet, or from supplements in order to maintain adequate levels. Vitamin D from sun exposure is the best way to optimize your vitamin D levels, however the majority of Americans do not get enough sun exposure.

As far as diet is concerned, it is very difficult to get enough vitamin D from food sources alone, as very few foods naturally contain vitamin D. The whole foods that do contain vitamin D (fatty fish, egg yolks, tuna, & mushrooms) will not contain enough to optimize your levels. And since vitamin D is a fat-soluble vitamin, a diet that is extremely low in fat may cause vitamin D deficiency (yet another reason to eat healthy fats). Therefore, supplements may be the answer to achieving optimal vitamin D levels.

Do I need to worry about vitamin D toxicity?

Taking vitamin D3 is very safe. Even the conservative Institute of Medicine has concluded that taking up to 10,000 IU per day poses no risk for adverse effects. Remember that if you take oral vitamin D, you also need to boost your vitamin K2, either through your food choices or a supplement. Vitamin K2 deficiency is actually what produces the symptoms of vitamin D toxicity, which includes inappropriate calcification that can lead to hardening of your arteries. If you are looking for a high quality supplement that includes both vitamin D and vitamin K, check out Vitamin D Supreme. This is a highly bioavailable capsule that includes 5,000 IU of vitamin D3 along with vitamins K1 and K2. If you have trouble swallowing capsules, you can take a liquid form of vitamin D. This is the supplement that I take. It is a highly bioavailable emulsion formula that contains 2,000 IU of vitamin D3 along with vitamins K1 and K2. Vitamin K works synergistically with vitamin D for optimal bone and arterial health and for maintaining proper immune balance.

Have you had your vitamin D levels tested?

​You must check your vitamin D levels often because assessing vitamin D status is one of the most important health-protecting steps you can take. If your serum levels are low, then you are at risk. 

What should my serum levels be?

​The first step to ensuring that you are receiving all of the benefits of vitamin D is to find out your levels. According to WebMD, 20-50ng/ml is considered an adequate range for a healthy adult, however this range is too low if you are trying to achieve optimal health. Above 20, you are safe from rickets. Above 30, your gums will be healthy. Above 40, you receive great cancer benefits. Dr. Joseph Mercola, an osteopathic physician and alternative medicine advocate, posits “If you’re using an oral supplement, recent studies suggest adults need about 8,000 IU’s of oral vitamin D3 per day in order to get serum levels above 40ng/ml.” New research shows that higher levels of vitamin D are necessary to provide protection from more serious chronic diseases such as cancer, heart disease, infections, multiple sclerosis and more. The range you are looking for is 50 to 70ng/ml.

​​There are two vitamin D tests -- 1,25(OH)D and 25(OH)D -- but 25(OH)D is the better marker of overall D status. It is this marker that is most strongly associated with overall health, and it is the one you should ask your physician for.

Sources:
Holick, M. (2005). The vitamin D epidemic and its health consequences. Journal of Nutrition. 135(11): 2739S-48S.
http://articles.mercola.com/sites/articles/archive/2011/11/21/how-to-get-your-vitamin-d-to-healthy-ranges.aspx
https://www.sciencenews.org/article/vitamin-d-essential-modern-indoor-lifestyle
http://www.scientificamerican.com/article.cfm?id=vitamin-d-deficiency-united-states.
http://wisemindhealthybody.com/dr-mercola/breast-cancer-prevention-vitamins/?cpt=dax