In the past year, I can't open a journal without seeing more and more evidence that we have been underestimating the benefit of Vitamin D on health and longevity.
Vitamin D is a fat-soluble vitamin that is naturally present in very few foods. It is also produced when ultraviolet rays from sunlight trigger synthesis in the body. Vitamin D obtained from sun exposure, food and supplements must then undergo two hydroxylations in the body to become active so it is a complicated process. A number of drugs interfere with Vitamin D synthesis also.
Vitamin D (along with Calcium) is essential for promoting bone health. But is also is important in neuromuscular and immune function and reduction of inflammation. It affects genes that encode proteins and other cells have Vitamin D receptors.
A new study from Archives of Internal Medicine reports low levels of Vitamin D are associated with cardiovascular disease, cancer and overall shortened longevity. Not only is this a big WOW but this applies to levels that are at the "lower" end of normal. So having Vit D levels in the lower quartile was an independent predictor of mortality in both men and women.
I am starting to check Vitamin D levels in all patients and I'm finding a high percentage of people who have levels that are too low. Sunlight, fortified milk, cereal, yogurt, eggs, salmon, tuna and mackerel are good sources of Vitamin D but may not be enough. Supplementing with 1000 mg of Vitamin D a day is often needed in addition.