Vitamin D: The Real Sunshine Vitamin Peter Kimble
Vitamin D is the only vitamin that can be manufactured from sunshine. Unfortunately, our indoor existence and fear of skin cancer has resulted in a nation where vitamin D deficiency is very common. While it has long been known that vitamin D is helpful in bone health, recent research actually shows that it reduces fractures in people who might be susceptible to osteoporosis. The latest research, however, shows that vitamin D3 deficiency is linked to a surprising number of other health conditions such as depression, cognition, muscle weakness, back pain, bone health, cancer, high blood pressure, fibromyalgia, diabetes, multiple sclerosis, rheumatoid arthritis, insulin resistance and pre-eclampsia in pregnancy, impaired immunity and macular degeneration. A number of studies have strongly suggested that vitamin D3 deficiency is associated with an increased risk of developing many forms of cancer including breast, ovarian, prostate and colon cancer.
Vitamin D is an important immune regulator, stimulating innate immunity and moderating inflammation. In a controlled trial of vitamin D supplementation to decrease bone loss in black women, a secondary finding was a significant reduction in the incidence of upper respiratory tract infections and influenza like illnesses among the women receiving vitamin D supplementation, particularly during the winter months. Vitamin D increases production of broad spectrum antimicrobial peptides while simultaneously preventing the immune system from releasing too many inflammatory cells into infected lung tissue
An analysis of the medical literature found that at least 1,000 to 2,000 IU of vitamin D3 per day is necessary to reduce the risk of colorectal cancer and that a low dose of vitamin D3 did not have the same protective effect. Current suggestions from the Institute of Medicine regarding Recommended Daily Intake (RDI) are considered by many experts to be much too low. Another challenge is the outdated acceptable upper limit for vitamin D3 consumption, which was set at 2,000 IU. However, researchers point out that more recent studies have shown that 10,000 IU is the safe upper limit.
A single, twenty-minute, full body (naked) exposure to summer sun will trigger the delivery of 20,000 units of vitamin D into the circulation of most people within 48 hours. The U.S. government requires fortified milk to be supplemented with vitamin D, but only with what we now know to be a paltry 100 units per eight-ounce glass. This would require drinking an unreasonable 8-10 glasses of milk to obtain an optimal amount of vitamin D.
Vitamin D deficiency is confirmed with a 25-hydroxyvitamin D level of less than 20 ng/mL . Vitamin D insufficiency is defined as a serum 25-hydroxyvitamin D level of 20 to 30 ng/mL. Many practitioners knowledgeable about Vitamin D believe that optimal levels would more likely be greater than 50 ng/ml. People concerned about their health should arrange to have their 25-hydroxyvitamin D levels tested.
Supplementation with vitamin D should be avoided by people with tuberculosis or other granulomatous diseases, metastatic bone disease, sarcoidosis, or Williams syndrome. People with a history of kidney stones should be conservative in supplementing with vitamin D.