For many adults, vitamin D may be in short supply

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For many adults, vitamin D may be in short supply

# Low sunlight exposure may be to blame for the deficiency. Supplements

or multivitamins are often the most practical solution.

By Sally Squires, Special to The Times

Most adults, especially those older than 50, appear to be falling short

on recommended daily levels of vitamin D, an essential nutrient long

known to preserve bones and now increasingly tied to protection against

other common ailments, including cancer and rheumatoid arthritis.

And just drinking more vitamin-D fortified milk or juice may not make

up the deficit, experts say.

A large, federally funded national health survey has found that vitamin

D intakes peak during childhood and teenage years but then decline.

Women ages 19 to 50 as well as men and women 51 and older ate the least

amount of vitamin D-rich food.

Even when the study accounted for use of vitamin D supplements, few

elderly men and women had intakes above the recommended daily levels.

The researchers concluded that the low intakes, especially for the

elderly, " warrant intervention. "

At a time when scientists are discovering a widening role for vitamin

D, " many lines of investigation indicate that most Americans do not

have optimal levels of vitamin D, mainly because of low sunlight

exposure, " said Walter Willett, chairman of the department of nutrition

at the Harvard School of Public Health.

Vitamin D is made by the skin, which requires ultraviolet light to

produce the vitamin from cholesterol.

Because of skin cancer concerns, however, more people wear sunblocks

that inhibit production of vitamin D. Dark-skinned people, whose skin

pigments protect them from the sun, need to spend a couple of hours in

sunlight to make enough vitamin D.

Plus, the skin's ability to make vitamin D declines significantly with

age. For that reason, the National Academy of Sciences set the latest

vitamin D daily intake at 200 international units (IU) — about the

amount found in two, 8-ounce glasses of skim milk — for those 19 to 50;

400 IU for those 51 to 70; and 600 for people 70 and older.

But a growing number of scientists believe that most adults 19 and

older may need 1,000 IU or more. And where research once suggested a

limited health role for vitamin D, today there is increasing evidence

that it protects against breast, colon and prostate cancer as well as

multiple sclerosis, lupus, rheumatoid arthritis and Type 2 diabetes.

" If just half the chronic diseases laid at the feet of vitamin D pan

out, it will be quite significant, " said P. Heaney, professor of

medicine at Creighton University in Omaha.

Just a decade ago, scientists developed an inexpensive blood test that

can accurately determine a person's vitamin D levels. Use of that test

revealed widespread deficiencies and led the National Academy of

Sciences to note that vitamin D " deficiency is now a significant

concern in adults over the age of 50 years who live in the northern

industrialized cities of the world. "

In 2004, the Dietary Guidelines scientific committee concluded that the

elderly, people with dark skin and those exposed to insufficient

sunlight " are at risk of being unable to maintain vitamin D status " and

may " need substantially more than the 1997 adequate intake for vitamin

D from vitamin D-fortified foods and/or vitamin D supplements. "

But some, including dermatologists, worry that the evidence is still

preliminary.

" Our recommendation is to take either vitamin pills or eat food that we

know has higher levels of vitamin D, " said Henry Lim, chairman of

dermatology at the Henry Ford Hospital in Detroit.

Here's how to safely boost vitamin D levels:

• Drink vitamin D-fortified beverages. Milk tops the list, but some

juices and soy milk are also fortified. (Yogurt and cheese are not

fortified with vitamin D.)

• Eat more herring and sardines. An ounce of pickled herring has

nearly 200 IU of vitamin D. Two small sardines have 65 IU. But not all

fish contains vitamin D. Salmon and tuna, for example, have none.

• Breakfast on fortified cereal or cereal bars. A cup of vitamin

D-fortified cereal has 40 to 60 IUs. Cereal bars have about 30.

• Take a multivitamin. It's the " most practical way to increase our

vitamin D levels, " said Harvard's Willett. Most multivitamins, even

those aimed at seniors, provide 400 IU of vitamin D, which won't meet

the needs of those 70 and older. But vitamin D supplements have 700 to

2,000 IU. The National Academy of Sciences sets a tolerable upper

intake of 2,000 IU for adults.