Vitamin D: How Important Is It?
Taking supplements to increase health, vigor, strength or just to feel better has been a part of the national debate for decades. Nutrition companies, the American Medical Association, Academy of Nutrition and Dietetics (formerly the American Dietetic Association) and even the Food and Drug Administration (FDA) have all weighed in on the debate on whether or not dietary supplements are necessary or even good for us. There seems little debate among these agencies that some supplements may actually be harmful and many common supplements on the market today have little or no proven benefit. So when the question comes up during our annual "Wellness" physicals whether or not we should be taking vitamin D supplementation, the answer will most often be, "it depends." It depends on which research studies physicians use as a reference for making recommendations to their patients or what new information has come to light regarding appropriate vitamin D levels. It can be a fairly confusing picture, especially for older individuals who don't get outside much--or for those of us that live in the Pacific Northwest with long winters and frequent overcast days.
But why worry about low levels of vitamin D? It turns out that the health benefits of vitamin D extend to at least 100 types of diseases, with the strongest evidence being that low levels increase the risk of many types of cancer, such as breast, ovarian, pancreatic, prostate and rectal. Low levels also affect cardiovascular disease, type 1 and 2 diabetes, respiratory infections such as flu and pneumonia, other infections such as sepsis, and autoimmune diseases such as multiple sclerosis. What's more, low levels of this vitamin affect mood, ability to lose weight, physical performance, immune system function and even increase our chances of dying by as much as 26% from all causes when compared to those with optimal levels of the vitamin.
Studies done a few years ago showed older men and women with low serum levels of vitamin D performed significantly worse than control groups on standard tests of balance and strength. When these same test subjects increased their vitamin D intake and were retested, they showed a significant improvement on the tests. But even though there is a massive amount of research on this critical vitamin, there is still relatively little consensus among doctors and major governmental health organizations as to exactly how much vitamin D should be taken in supplement form, if at all. For individuals living in sunny climates who have regular exposure to sunlight, there is probably little need to supplement their vitamin D since just a few hours of sun exposure leads the body to make about 10,000 IUs of the vitamin.
However, for those adults living in northern climates and especially for seniors who have little exposure to sunlight, 1,000 IUs up to 2,000 IUs per day is generally accepted as a safe dosage. But ideally this intake is determined by a blood test done by a doctor to determine the right dosage for each individual. For example, it took my primary care doctor several months of follow-up lab testing to determine that I needed 4,000 IUs per day to get my blood levels up to a "normal" level. Every individual is different and the ideal dosage needs to be established by doing blood tests that guide doctors in determining the optimal dosage for each patient. So if you can't get outside for several hours of sun exposure each day, the next best thing is to make an appointment with your provider to have your vitamin D level checked. It could add many years to a life, as well as, to the quality of that life!