Vitamin D also fights infections, including colds and the flu, as it regulates the expression of genes that influence your immune system to attack and destroy bacteria and viruses. In this interview above, Dr. Holick expounds on these and many other health benefits of vitamin D. For instance, optimizing your vitamin D levels can help protect against:
Cardiovascular disease. Vitamin D is very important for reducing hypertension, atherosclerotic heart disease, heart attack, and stroke. According to Dr. Holick, one study showed that vitamin D deficiency increased the risk of heart attack by 50 percent. What’s worse, if you have a heart attack and you’re vitamin D deficient, your risk of dying from that heart attack creeps up to nearly 100 percent!
Autoimmune diseases. Vitamin D is a potent immune modulator, making it very important for the prevention of autoimmune diseases, like multiple sclerosis and inflammatory bowel disease.
Infections, including influenza. It also helps you fight infections of all kinds. A study done in Japan, for example, showed that schoolchildren taking 1,200 units of vitamin D per day during winter reduced their risk of getting influenza A infection by about 40 percent. I believe it’s far more prudent, safer, less expensive, and most importantly, far more effective to optimize your vitamin D levels than to get vaccinated against the flu.
DNA repair and metabolic processes. One of Dr. Holick’s studies showed that healthy volunteers taking 2,000 IUs of vitamin D per day for a few months up-regulated 291 different genes that control up to 80 different metabolic processes, from improving DNA repair to having effect on autoxidation (oxidation that occurs in the presence of oxygen and/or UV radiation, which has implications for aging and cancer, for example), boosting your immune system and many other biological processes.