Steady intake of vitamin D a must for adults

My 78-year-old father, who lives with me, has been diagnosed with osteopenia, described by his doctor as a mild thinning of the bones -- not as severe as osteoporosis but perhaps the first step toward it.

The doctor told me to try to increase his calcium intake, but then a friend told me that Dad may need more vitamin D. The doctor didn't mention this to me and has not returned my call. Do you know where I could find good information on this?
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A: Based on the information we have found, it appears that your friend is correct. Because vitamin D promotes the absorption of calcium, a vitamin D deficiency contributes to osteoporosis.

According to the National Institutes of Health (NIH), people with vitamin D insufficiency absorb less than 10 percent of available calcium. In other words, even if you have an adequate intake of calcium (which for men and women over 50 is 1,200 mg daily), you might not absorb it effectively if you have low levels of vitamin D.

Vitamin D deficiency is most often seen in post-menopausal women and older adults. (It's estimated that as many as 30 to 40 percent of older adults with hip fractures are vitamin D insufficient. The insufficiency rate is especially high among the elderly living in nursing homes.)

While most people know that women are at risk for osteoporosis, only 39 percent of Americans believe the same to be true for men, according to a recent study brought to our attention by Tropicana, the orange juice maker that sells calcium enriched juices. But 20 percent of those affected by osteoporosis are men. So while your Dad doesn't yet have osteoporosis, he could be at risk for the disease, defined as having low bone density and therefore having bones that are prone to shatter.

How much vitamin D is enough? At the moment, most medical authorities say that average adults need 200 IU (International Units) of vitamin D daily, while adults over age 50 need 400 IU and people over 70 years of age need 600 IU daily. (The upper safe level of vitamin D, according to Dr. Mark Andon, director of nutrition for Tropicana, is 2,000 IU daily.)

How does one get an adequate amount of vitamin D? Sunshine is a significant source, and 10 to 15 minutes of sun exposure at least twice a week to the face, arms, hands or back is usually sufficient to provide adequate vitamin D, says the NIH. But if you slather on sunscreen with a sun protection factor (SPF) of 8 or greater to block the sun's UV rays -- and this is very important to protect against skin cancer -- the ability of the body to synthesize the rays into vitamin D is blocked. So, if you choose the sun route to get enough vitamin D, follow the 10 to 15 minutes of sun exposure with a sunscreen of at least 15 SPF to protect yourself from the sun's negative effects.

Something else to know about the sun and vitamin D: As we age and our skin thins, our body's ability to make vitamin D from sunlight decreases, says Dr. Andon. He adds that people living in northern climes will not be able to get as much vitamin D from exposure to the sun as, say, people living near the equator.

So, how else to obtain vitamin D? There are food sources, such as fortified orange juice, cod liver oil, fatty fish (salmon, tuna, mackerel and sardines), fortified milk and fortified breakfast food products such as yogurt and cereal. But it's often difficult to obtain enough vitamin D from natural food sources. So vitamin D supplements, which you can buy over the counter at pharmacies, health food stores, and supermarkets, are often recommended.

One final note: NIH warns that high caffeine intake (defined as more than 300 mg per day of caffeine, equivalent to approximately 18 ounces of caffeinated coffee) may accelerate bone loss, because caffeine is thought to inhibit vitamin D receptors.

A new study released earlier this month out of Creighton University indicates that high amounts of vitamin D may well reduce the risk of several types of cancer for older women by 60 percent. The amount of vitamin D used in the study was 1,000 IU daily, and more studies are needed to determine whether the study holds true for large groups of men as well as women, researchers say. Still, the study results are considered significant.
source:www.post-gazette.com