June is here and with it, so far, abundant sunshine. On many levels, that is good news, especially as we are more likely to get adequate Vitamin D exposure.
Vitamin D is often called the “sunshine vitamin” because it is produced from cholesterol via a chemical reaction catalyzed by sunshine on skin. People who live north of a line connecting San Francisco to Philadelphia, like us, tend to have inadequate levels of Vitamin D in their blood. Ditto for people with darker skin.
Why is Vitamin D important? First, it is vital for strong bones. Deficiency can lead to osteoporosis with weaker bones that are more prone to fracture. Rickets, softening and weakening of the bones in children (basically osteoporosis of the young), is making a resurgence in industrialized nations as we slather our children with sunscreen. Heart disease is also more common in the Vitamin D deficient. Type 1 diabetes is another disease that is more prevalent in those living in the north — 400 more times as common in Finland as in Venezuela, for example. Finnish kids given a Vitamin D supplement had a 90 percent decrease in the risk of developing diabetes than children not given the supplement!
Cancer is another disease where Vitamin D may be helpful. The strongest association is with Vitamin D and colon cancer; once again, the incidence of colorectal cancers is higher the farther north one lives. Near and dear to my heart, women with higher Vitamin D levels at the time of diagnosis with breast cancer had better survival rates! Lab studies have shown that Vitamin D can decrease cancer cell growth rate, decrease the formation of new blood vessels that cancers need to grow and spread, and increase the death of cancer cells (apoptosis). Many older studies did not show an improvement in cancer rates with Vitamin D supplementation, but very low doses were used. The VITAL study to look at this again with doses more reflective of what the science suggests is needed is ongoing — results are expected in two years.
How much Vitamin D is enough? Vitamin D is found in fatty fish like salmon and tuna as well as most milks and cereals (which are fortified with this important nutrient). Most studies suggest taking between 800 – 2000 IU daily — or getting 15 minutes of sun exposure daily before putting on sunscreen.
It is a good idea for most of us to have a simple blood test to evaluate Vitamin D levels. With this information, your doctor can suggest a supplement dose that is right for you. And yes, too much of a good thing can be a bad thing. One study of women given a whopping 500,000 units of Vitamin D in a once-a-year dose indicated that these women had a 26 percent increase in the risk of a bone fracture and a 15 percent higher risk of falling! My office offers testing to the entire community, male or female. Knowledge is power, so get your Vitamin D levels tested today!
Dr. Kelly Shanahan is a board certified gynecologist and the owner of Emerald Bay Center for Women’s Health, located at 1154 Emerald Bay Road. Call 530-542-4961 to schedule your Vitamin D testing!