Why should we be concerned about Vitamin D deficiency?

New research has shown that vitamin D deficiency is epidemic in American adults today, suggesting that up to 90 percent of North Americans are vitamin D deficient. It is likely that over-usage of sunscreen in climates and seasons when sunburn is not a possibility has contributed to this epidemic. This is especially significant because:

• A 2006 systematic review of 63 studies on vitamin D status in relation to cancer risk has shown that vitamin D sufficiency can reduce one’s risk of colon, breast and ovarian cancers by up to 50 percent. The landmark paper, published in the February 2006 issue of The American Journal of Public Health, is the most comprehensive paper on vitamin D written to date.
• Additionally, vitamin D deficiency is a leading cause of osteoporosis, a disease affecting 25 million Americans which leads to 1 million hip and bone fractures every year. In elderly individuals, such fractures are often deadly. Encouraging everyone to wear sunscreen all year long in any climate undoubtedly is contributing to this problem, as vitamin D is necessary for the body to properly process calcium.
• While environmental correlations have established for years that people in sunny climates have lower risks of many forms of cancer, in recent years the mechanism by which Vitamin D slows or retards the growth of tumor cells has been researched and identified. It was once thought that only the kidneys could produce active vitamin D, but we now know that many cells in the body perform this function, including cells in the breast, prostate, colon, brain and skin.
• Research has shown that the active form of vitamin D, when present in cells throughout the body, inhibits the growth and spread of abnormal cells, including cancer cells.