Vitamin D -- one of the most talked about nutrients of the past few years -- is back in the spotlight.
The first formal recommendations for daily intakes of calcium and vitamin D for bone health were released this week in a report from the Institute of Medicine.
Many Americans are getting enough of these nutrients, except for adolescent girls who may not consume enough calcium and some elderly folks who don't get enough of either, says the report by a panel of experts. Fortified foods and supplement use help, and sunlight triggers the production of vitamin D and contributes to people's levels.
But several top national nutritionists say many people will need to fine-tune their diets to reach the vitamin D recommendation of 600 International Units (IUs) a day with food alone, especially if they don't drink much milk or eat a lot of fish.
"There's no way that people will satisfy those recommendations for vitamin D without supplements," says Elizabeth Ward, a registered dietitian in Boston. There are very few dietary sources of vitamin D, she says, but some of the more accessible ones include fortified milk and soy beverages, fortified orange juice, eggs, salmon and tuna.
Many cereals are fortified with 40 IUs or more of vitamin D a serving, and milk and fortified alternatives have about 100 IUs a cup, says Keith Ayoob, a registered dietitian at the Albert Einstein College of Medicine in New York. "Many multivitamins have 400 IUs per dose, so a good multi will really give you a leg up."
To consume 600 IUs of vitamin D with a single food daily, you would need to eat or drink six cups of milk or 15 servings of most cereals that have been fortified with vitamin D, says Joy Bauer, a registered dietitian in New York. She's not suggesting eating this way, just pointing out how hard it would be reach the goal.
It takes focus to get enough
For people who are big milk drinkers or frequent eaters of fatty fish like salmon and sardines, a supplement is probably not necessary, but others may need one to meet the recommendation, Bauer says.
Bauer has milk on cereal and eats wild salmon several times a week, but she also takes a daily multivitamin with 1,000 IUs of vitamin D.
Ward also takes a vitamin D supplement every day, and she gives her three daughters a chewable vitamin D supplement that contains 400 IUs. They also drink three cups of low-fat milk a day, so they are consuming about 700 IUs of vitamin D, she says.
Endocrinologist Clifford Rosen, who was on the committee that developed the new recommendations and is a senior scientist at Maine Medical Center Research Institute in Scarborough, says, "It's possible to meet the requirement with just food, but it requires motivation in terms of focusing on what you eat."
Obesity linked to lower levels
One other way to help your vitamin D level is to maintain a healthy weight, he says. Obesity is associated with lower levels of the nutrient, so if you lose weight, your vitamin D levels will likely improve.
Vitamin D has been a hot topic in recent years because research has linked lower levels of the nutrient to certain cancers, diabetes, and bone and immune system problems.
The panel concluded that more research is needed into the potential health benefits of even larger amounts of vitamin D than the new recommendation.
The committee set the upper limit for vitamin D at 4,000 IUs a day for those ages 9 and older. This is considered the safe boundary and is not the amount people should strive for, the panel cautions.
Excessive vitamin D can damage the kidneys and heart.
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