>What you should know about Vitamin D

9 06 2010

>You may be surprised to learn that active vitamin D is actually a hormone. Vitamin D receptors have been found in the brain, heart, skin, and white blood cells. The reproductive organs such as the ovaries, breasts, testes, and prostate gland also contain vitamin D receptors.

Vitamin D performs several functions in your body. It has long been known that vitamin D regulates calcium and phosphorous in the bloodstream and promotes bone formation and mineralization. New research is revealing the role vitamin D plays in the immune system. For example, vitamin D enhances phagocytosis, a process by which certain white blood cells engulf bacteria, dead cells, and other debris. Vitamin D also plays a role in preventing autoimmune diseases. Low vitamin D has been associated with rheumatoid arthritis, lupus, Crohn’s disease, ulcerative colitis, multiple sclerosis, psoriasis, and fibromyalgia. People who suffer from muscle and chronic pain, psoriasis, heart disease, and breast, prostate, and colon cancers are also more likely to have low vitamin D levels.

Perhaps the most exciting research about vitamin D is its ability to prevent some cancers. Vitamin D appears to play a role in cell proliferation (division) and differentiation (making sure dividing cells don’t become cancerous cells). In addition, vitamin D is involved in proper death of unhealthy or old cells, a process known as “apoptosis,” and in the prevention of blood vessel formation to feed existing cancers, known as “angiogenesis.”

The first randomized, placebo-controlled trial evaluating vitamin D supplementation and the incidence of cancer was published, in 2007—in that study, women using 1100 IU of vitamin D3 daily for 4 years had a 60% lower cancer risk than the placebo group. When patients who were diagnosed with cancer during the first year of the study were excluded (with the assumption that they likely had cancer when they entered the study), the reduction was 77%. This is exciting news since there aren’t many supplements that have been shown to lower cancer risk by such a large margin.

Vitamin D is also an important anti-aging hormone since it actually slows the shortening of your telomeres —the end segments of chromosomes that protect your DNA. Optimal vitamin D levels are thought to slow your speed of aging by at least 5 years.

Your skin makes vitamin D from exposure to the sun. As you age, however, your skin becomes less able to make vitamin D. When taking vitamin D, it’s important to measure and monitor vitamin D levels closely. Too much vitamin D can cause calcification of soft tissues and an increased risk of kidney stones. It’s especially important to monitor your levels if you are supplementing with doses greater than 2,000 IU of D3 per day.

You can find additional information about Vitamin D3, Hormones, and Optimal Aging please visit my website or purchase a copy of my new book by calling our office.

In Health.

Dr. Kathryn Retzler