A growing body of research indicates that vitamin D deficiency contributes to a broad spectrum of conditions such as high blood pressure, poor insulin sensitivity, inflammation, and other fundamental processes that underlie heart disease.
Alarmingly, vitamin D deficiency is extremely common throughout the population—affecting more than half of adults and the majority of the elderly
Sunlight, Vitamin D, and Heart Attack
The farther north you live, the more likely you will suffer a heart attack. That curious observation led to the suspicion that vitamin D may somehow be related to the development of heart disease. It suggests that sunlight exposure may somehow provide a protective effect, perhaps through vitamin D. The notable exception to this pattern is the Eskimos, who eat large quantities of oily fish, a rich source of vitamin D and omega-3 fatty acids
Health-Promoting Effects of Vitamin D
- Normalizing blood pressure. People deficient in vitamin D are much more likely to have high blood pressure. Treatment with vitamin D and calcium significantly lowers systolic blood pressure. Vitamin D likely exerts this effect by suppressing the expression of the blood pressure hormone renin
- Anti-inflammatory effects. Vitamin D appears to have a potent effect on reducing inflammation, as measured by C-reactive protein (CRP). Dramatic reductions in CRP have been documented. In contrast, statin medications may only produce modest decreases in CRP levels
- Anti-diabetic effects. Diabetes is more prevalent in individuals with low serum vitamin D levels. Vitamin D administration reduces blood sugar and increases sensitivity to insulin. Improvement in insulin sensitivity is associated with a cascade of benefits, including a decreased risk of developing full-blown diabetes
Optimizing Vitamin D Levels
The best way to know your vitamin D status is to have your doctor measure the blood level of 25-hydroxyvitamin D (not to be confused with 1,25-dihydroxyvitamin D).Dr. Michael Holick of the University of Boston proposes that serum level of 25-hydroxyvitamin D is in the range of 30-50 ng/mL (75-125 nmol/L).
Ten minutes of sun exposure in midday, wearing shorts and t-shirt to expose skin surface area, will provide most Caucasians plentiful vitamin D during the summer. This limited time minimizes the risk of skin cancer. (If you are especially fair-skinned, you might do fine with somewhat less.) If you are in the sun any longer than this, you should apply a sunscreen (which blocks both sunlight as well as vitamin D activation in the skin).
However, if sun exposure is sporadic, supplementation is crucial to obtain the full benefit of vitamin D’s panel of biologic effects.
-Adapted from article by Dr William Davis, a cardiologist practicing in Milwaukee, Wisconsin.
LE Magazine Sept 2007. for full article, read here