Vitamin D: Vital Role in Your Health
Researchers conclude the "sunshine vitamin" is good medicine.
Your D-Day Plan of Attack
Many vitamin D researchers are convinced the government's recommendations
for adequate vitamin D intake are far below what your body really needs. Those
guidelines call for 200 IU a day up to the age of 50, 400 IU from 51 to 70, and
600 IU over age 70.
But, says Holick, studies show that to achieve blood levels of vitamin D
that can protect you against chronic diseases, you need an optimal dose of
1,000 IU of vitamin D a day. The vitamin is well absorbed from foods like
fortified milk and from vitamin pills, whether taken alone or in combination
with other foods.
So how can you get enough of this overlooked vitamin? Most foods aren't
filled to the brim with vitamin D -- far from it. You can get 425 IU in a
3-ounce serving of salmon, and 270 IU in 3.5 ounces of canned sardines. But
most foods provide much more modest amounts of vitamin D, from egg yolks (25 IU
per egg) to cheddar cheese (2.8 IU per ounce).
"You'll get 200 IUs of vitamin D by drinking two glasses of fortified
milk," says Sandon, spokeswoman for the American Dietetic Association. But
at age 70, even reaching the government's recommended level of 600 IU from diet
alone can be a challenge. "These people are probably not drinking six
glasses of milk a day for various reasons, including a higher incidence of
lactose intolerance in the elderly," she tells WebMD.
"We need more food fortification [with] vitamin D," says Susan
Sullivan, DSc, RD, assistant professor in the department of food science and
human nutrition at the University of Maine. "We need to make it easier for
people to meet their vitamin D requirements through the food supply."
Some of that fortification is already happening. In addition to milk, a
growing number of food manufacturers are adding vitamin D to yogurt, breakfast
cereal, margarine, and orange juice. A cup of fortified orange juice, for
example, contains 100 IU of vitamin D.
Here Comes the Sun
If you're striving for Holick's recommendation of 1,000 IU a day, you may
have to turn to vitamin D supplements or the sun as your vitamin D savior.
Regular sun exposure can stimulate the human skin to produce quantities of
vitamin D that far exceed your needs. Without a shadow of a doubt, sunlight is
the largest single source of vitamin D for most people.
But before you grab the beach towel and head for the seashore, keep in mind
that particularly in the higher northern latitudes, vitamin D levels can be
problematic. If you live above 40 degrees north latitude -- north of
Philadelphia, for example, or Denver -- you won't make much of any vitamin D in