Vitamin D Dilemma

The Vitamin D Dilemma

As long as we started posting information about supplements it seems totally appropriate to talk about vitamin D.

Lots of news about vitamin D lately, particularly regarding whether sun exposure is a beneficial source of vitamin D.  First, there’s more research that points out a deficiency of vitamin D is more harmful than once believed – it’s not just for strong bones but also prevents breast, prostate and colon cancer.  On the other hand are those who point out that exposure to the sun isn’t good for you either because of the higher risk of skin cancer. Now the more recent research states that when people take Vitamin D supplements they appear to have a lower risk of dying from any cause.

The Tufts Health & Nutrition Letter, back in December 2007, reported that those who took vitamin D had a 7% lower risk of death than those who didn’t and the benefit was slightly higher – 8%- for those taking vitamin D three or more years.

What was interesting was the variation of doses; they ranged from 300 to 2000 international units (IU).  Most commercial OTC (over the counter) bottles average about 500 IU. What’s more the study found no negative effect from taking up to 1,000 IU daily. Today, vitamin D researchers such as Dr. Joel Finkelstein of Massachusetts General Hospital suggest people of all ages should get 800 units of vitamin D or more, the equivalent of 8 cups of milk or 2 vitamin D. supplements.

Researchers at the University of California –San Diego also published results of another study, this one comparing breast and colon cancer rates with average (from the sun) wintertime vitamin D levels.  They reported that cancer rates tend to fall with higher vitamin D. rates.  The researchers estimated that by increasing the dosage of vitamin D, 85,000 cases of breast cancer and 60,000 cases of colon cancer could be prevented annually.  They also suggested for the winter that people take a combination of foods with high levels of vitamin D, supplements and short intervals – 10-15 minutes –in the sun.

The study also found that US adults intake of vitamin D averages about 230 IU daily and that includes the less potent vitamin D2, ( the type synthesized by plants) still used in some multivitamins instead of the preferred D3 (the type synthesized by humans in the skin).  The researchers report that the upper limit of vitamin D should be closer to 2000 to 3000 IU daily.

Others debate whether the large increase in the dosage is needed.

Vitamin D’s purpose is to maintain normal blood levels of calcium and phosphorus.  Vitamin D helps the absorption of calcium which helps form and maintain strong bones.  Recent research also suggests vitamin D may provide protection from osteoporosis, hypertension, cancer and several autoimmune diseases. Although adult bones are no longer growing, they are in a constant state of turnover, where bone mineral is lost

People at high risk for vitamin D deficiencies are the elderly, dark skinned, obese, and those who get no exposure to the sun. Vitamin D deficiency has also been associated with muscle weakness and pain for both adults and children.

This is the sunshine vitamin so called because it is synthesized in our skin when we are exposed to direct sunlight. My problem is I wear sunblock to prevent cancer and sunblock impedes this synthesizing process.

Vitamin D is well known for enhancing bone health and regulating some of the calcium levels, but recent research shows it does a lot more than that. Scientists  now link this fat soluble nutrient to several functions throughout the body including working with your brain. For instance, it is now known that vitamin D activates and deactivates enzymes in the brain and may protect neurons and reduce inflammation.

As reported in the November/December 2009 of Scientific American Mind, one new European study showed that subjects, aged 65 and older, with lower vitamin D levels were twice as likely to be cognitively impaired compared to those with optimum levels of vitamin D. Another study with subjects, aged 40 to 79, showed that those people with lower vitamin D. levels processed information much slower regardless of their age.

This information is important because cognitive impairment is usually the first step before dementia and Alzheimer’s disease. Researchers interested in this topic are engaged in new research. As for me, I am trying to figure out what dosage is best.  My doctor says 1000 to 2,000 IU daily, which is about the amount your body will synthesize with 15 to 30 minutes of sun exposure two or three times a week. Keep in mind, however, that skin color, where you live (the sun is less strong the more north you live) and how much of your skin is exposed all affect how much vitamin D you can produce.

A suggestion: talk to your doctor about how much vitamin D you need.

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