You don’t have to walk around naked outdoors to get a healthy dose of vitamin D, healthcare professionals say. Though nudists may ignore this advice, all we need is about 15 minutes of sunshine on our face, arms and legs (wearing a t-shirt and shorts) every day without sunblock.
Sunshine facilitates conversion of inactive to active vitamin D in the skin that promotes phosphorus and calcium absorption in our intestines. This action helps to maintain strong bones and prevent rickets and osteomalacia, two diseases that weaken bones. A lack of vitamin D also can increase the risk of heart disease, high blood pressure, and breast and prostate cancer.
New research has also shown that vitamin D also helps prevent birth defects like spina bifida and aids the body’s immune system.
“Vitamin D enables the P53 gene to function,” says Michael Roizen, M.D., Chairman of Cleveland Clinic’s Division of Anesthesiology, Critical Care Medicine and Comprehensive Pain Management, and author of You:
The Owner’s Manual.
“P53 is the proofreader gene; it functions like a spell-checker on a computer,” he says. “You have more than 300 million cell duplications every day in your body, and sometimes the body makes a few ‘spelling errors’ in those cells. The P53 gene notifies your cells that there’s a mistake, and tells your cells to correct it.” Left unchecked, these “typo” cells can become cancer cells.
There are three things to remember when trying to get your vitamin D from the sun:
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Do not use sunblock for those first 15 minutes of sun exposure. Sunblock prevents inactive vitamin D from being converted by the skin. If you must be outside for longer than 15 minutes, then do put on sunscreen.
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More sunshine is not better – getting sunburned does not mean you are getting more vitamin D. In fact, overexposure to the sun can lead to skin cancer.
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The best time to get healthful sun in Cleveland is between 1 and 2 p.m. between April 15 and October 1. “Between October 1 and April 15, the sun doesn’t have enough energy to facilitate conversion to active vitamin D for anyone who lives north of Atlanta,” Dr. Roizen says.
We also can get our daily dose of vitamin D through foods like fatty fish - salmon, mackerel, tuna and sardines – and vitamin D-fortified milk (one cup supplies one half of the recommended daily intake for adults between the ages of 19 and 50; one-fourth of the recommended intake for adults 51-70; and 15 percent for folks over 71) and vitamin supplements.
Cindy Moore, M.S., R.D., Director of Nutrition Therapy at Cleveland Clinic, recommends 5 micrograms (200 international units) of vitamin D a day. As we get older our need for vitamin D increases, so people aged 51-70 need 10 mcg (400 IU) a day and those over 70 need 15 mcg (600 IU).
But don’t overdo vitamin D intake, Moore cautions. Vitamin D is fat soluble, and when you consume too much, it stays in the body and can cause harmful effects.
“Too much calcium in the blood is rarely caused by food and supplement intake alone. Usually it is caused by a disease related to the regulation of calcium. But too much calcium in the blood can cause calcium deposits in soft tissues in heart, lungs and kidneys,” she says. “
For example, when heart tissue calcifies [hardens], the heart doesn’t pump as well.”
And that’s the naked truth.
© Copyright 1995-2008 The Cleveland Clinic Foundation. All rights reserved
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 10/1/2006
