Have you heard about Vitamin D3?

Vitamin D, its technical name is 1, 25-hydroxyvitamin D, is the vitamin most widely known as being needed for strong bones. Vitamin D3, called cholecalciferol, is the most bio-active form of this vitamin, is synthesized by humans in the skin upon exposure to ultraviolet-B radiation from sunlight, or it can be obtained from the diet and/or supplementation. It is a fat-soluble vitamin, along with vitamins A, E and K, and is essential for maintaining normal calcium metabolism.

Vitamin D is itself, biologically inactive and must be metabolized to its biologically active forms. When Vit D is consumed in the diet or synthesized in the skin, it enters the blood stream and is transported to the liver where the liver converts it into the active form 1, 25-hydroxyvitamin D [25(OH)D], the major circulating form of it. Increased exposures to sunlight or dietary intake increases blood levels making the concentration useful biologically.

However, the story does not end there. Researchers are finding many new and exciting things about this vitamin. Low levels of Vit D3 have, for example, been found to be concurrent with depression (May, 2008; the American Medical Association journal Archives of General Psychiatry) in people 65 years of age and older. The low findings were found in addition to elevated parathyroid hormone levels, which low Vit D3 levels affect.

In another large study, there was a relationship between increased Vit D3 levels and lower incidence of colorectal cancer. It has also been discovered, at the Univ. of Rochester Medical Center (June 15, 2006; International Journal of Cancer), that Vit D3 causes specific genes to increase their enzyme production that protects healthy prostate glands from damage or injury that may lead to cancer. This means that Vit D3 may be useful as treatment and in prevention.

There’s been a connection between Vit D3 and breast cancer. Vit D3 is associated with blocking the effects of estrogens in women who have a gene known as Taql, a polymorphism (a polymorphism is variant of a normal gene), which renders these women more susceptible to breast cancer. Vit D3 regulates cell growth, cell differentiation and programmed cell death, needed for cells to regulate any abnormal development, which is what cancer is.

The American Journal of Clinical Nutrition (Am J Clin Nutr. 2007; 89:1420-5) reported this study relating the levels of Vit D3 and telomere length; longer telomere lengths are known to be associated with longer life. A telomere can be explained by making this analogy; if your shoe string is chromosome/DNA the plastic tip on the end of that shoe string is the telomere equivalent. It, the telomere, prevents the shortening of the chromosome/DNA strand (just like the plastic tip of the shoe string prevents the shoe string from unraveling) when the cell replicates. Of the women who were studied and had higher use of Vit D3 supplementation were found to have longer telomeres.

Several important facts need to be discussed. When you purchase supplemental Vit D make certain it’s the active form Vit D3. The amount of Vit D3 one should take daily is about 1000 IU to 2000 IU. African Americans should take more Vitamin D3 starting at 2000 IUs up to 5000 IUs. The exact amount should be determined by your current Vit D3 level, which can be assessed by a blood test and your healthcare provider. However, beginning at the former dose is a good place to start. Read, “African American Healthy” by Richard W. Walker, Jr. MD, MBA; Square One Publisher, 2011.

By Richard W. Walker, Jr. MD