Good Morning Sunshine: Waking up to the Benefits of Vitamin D

Any nutrition book will tell you that vitamin D is an important nutrient for healthy bones and teeth. But can it help you live longer? A study just published in the Archives of Internal Medicine reports that research subjects who added a vitamin D supplement to their diets had a 7 percent lower risk of death than those who did not.

The authors looked at 18 published articles, which included close to 60,000 patients taking "D" supplements. Each took a typical daily supplement dose - about 500 international units (IU) - for an average of 5.7 years. Many had chronic conditions and diseases, including diabetes, cancer and heart disease.

The explanation behind these findings is still unclear, and more research is needed. One popular theory is that vitamin D may block cancer cells from spreading. It may also stop plaque from growing as quickly in blood vessels, a factor in heart disease. Vitamin D also plays an important role in the health of bones, kidneys and the immune system.

Getting more vitamin D
It is easy to be lacking in vitamin D. Food sources with the vitamin are limited. Also, your body cannot make vitamin D on its own. It needs the sun to help convert it to a usable form. Adults who spend a lot of time indoors, live in northern climates or are homebound may be short of vitamin D. With winter on our tail now, shorter days and fewer hours of sunlight are making it harder to get needed sun.

Review these tips before buying vitamin D supplements or throwing out your hat and sunscreen:

1. Let the sun shine in

Any sunscreen over an SPF of 8 blocks the body's ability to absorb vitamin D. By all means, don't throw out your sunscreen, which you need for cancer and anti-aging protection. But remember that some unprotected time in the sun is good for you. As little as 15 to 20 minutes a day without sunblock is enough to provide your daily requirements if you are light-skinned. African Americans and darker-skinned people need 30 to 40 minutes of sun

2. Target food sources that are high in vitamin D

Foods that are rich in vitamin D include:

• Fatty fish, like mackerel, sardines and salmon
• Eggs, cereal, and fortified milk and juice


3. Consider a vitamin D supplement

Look for a supplement with at least 200 IU of vitamin D, or higher if you get little sun or your diet is lacking in D. The Institute of Medicine recommends:

• 200 IU daily up to age 50
• 400 IU from ages 51 to 70
• 600 IU for those over age 70

For seniors at risk for hip fractures or who have low vitamin D levels, 800 IU may be advised. Ask your doctor what dose is right for you.

Be aware that more than 2,000 IU (or 1,000 IU in children under one year of age) can cause nausea, vomiting, constipation and other problems. Higher doses can raise the calcium in your blood to dangerous levels, too, harming your brain, heart and kidneys.

Those warnings aside, it's time to give vitamin D a grade of "A." Ask your doctor if you are getting enough. A simple blood test will show if you have an optimal level or need more of the vitamin.

Related Articles A Vitamin for Your Bones Do Seniors Need Dietary Supplements? Preventing Skin Cancer It's Never Too Late for Calcium

External Sources Autier P, Gandini S. Vitamin D supplementation and total mortality: a meta-analysis of randomized controlled trials. Archives of Internal Medicine. 2007;167:1730-1737. Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol. American Journal Clinical Nutrition. 2003;77:204-210. Vieth R. What is the optimal vitamin D status for health? Progress in Biophysics and Molecular Biology. 2006;92:26-32. National Institutes of Health. Dietary supplement fact sheet: vitamin D. Accessed September 20, 2007.

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