Too little of the sunshine vitamin linked to heart disease,
statin-related muscle pain, other conditions.
Heart disease. Falls and broken bones. Breast and prostate
cancer. Depression and memory loss. These problems seem to have
nothing in common, except that they are leading causes of
faltering health and death. Exciting research suggests there
is a link — too little vitamin D, the so-called sunshine
vitamin, can contribute to all of these.
Millions of Americans, especially older ones, don't have enough
vitamin D in circulation. Current national recommendations for
daily vitamin D intake — 400 international units (IU) for those
aged 51 to 70 and 600 IU for those older than 70 — may not be
high enough to reverse this trend.
Many older Americans don't get enough vitamin D. It
is as important for the heart and overall health as
it is for bones.
A daily supplement that provides 800 to 1,000 IU is
the simplest way to get more vitamin D; getting more
sunlight also helps.
Making vitamin D
Vitamin D isn't really a vitamin. It is a hormone the body makes
in assembly-line fashion. Sunlight striking the skin converts a
cousin of cholesterol into pre-vitamin D. As this circulates
through the bloodstream, the liver turns it into biologically
inactive 25-hydroxyvitamin D. (This is what is measured to
determine your vitamin D status.) The kidneys then supply a small
chemical tweak, creating the active vitamin D that can affect
cells throughout the body.
The amount of 25-hydroxyvitamin D you have in circulation depends
on how much sunshine you get, your skin pigmentation (darker skin
reduces vitamin D production), your diet (salmon and other fatty
fish are rich in vitamin D), and your age (the older you are, the
less vitamin D your skin makes).
Experts have defined three categories for vitamin D status:
deficient, less than 20 nanograms of 25-hydroxyvitamin D
per milliliter of blood (ng/mL); insufficient, from 20
to 30 ng/mL; and sufficient, above 30 ng/mL.
Surveys suggest that at least one-third of American adults, and
75% of adults with cardiovascular disease, fall into the
Vitamin D is best known for helping the digestive system absorb
calcium and phosphorus. That's one way it helps build and
maintain healthy bones. But it does much, much more.
Coronary artery disease. Deposition of
calcium in arteries, a process that stiffens arteries, is more
likely to happen in people who are low in vitamin D. In the
Harvard-based Health Professionals Follow-up Study, men low in
vitamin D were twice as likely to develop heart disease as those
with plenty of the vitamin in circulation.
High blood pressure. Active vitamin D
decreases the kidneys' production of renin, a hormone that boosts
blood pressure. Several studies suggest that low vitamin D
contributes to high blood pressure, and that getting more of the
vitamin can help control blood pressure.
Heart failure. Most people with heart
failure are deficient in vitamin D. Getting more could help
strengthen heart contractions.
Statin-related muscle pain. Some people
who take a cholesterol-lowering statin stop because of muscle
pain. In a study of 128 men and women with statin-related muscle
pain, two-thirds of them had 25-hydroxyvitamin D levels under 20
ng/mL. Among those who took a vitamin D supplement while
continuing the statin, muscle pain disappeared in 90%.
Infection. Preliminary trials suggest
that too little vitamin D can leave the body prone to infection,
and having enough in circulation can help the body fight off the
flu, tuberculosis, and infections of the upper respiratory tract.
And more. A deficiency in vitamin D has
been linked to some types of cancer, type 2 diabetes, depression,
osteoporosis, falls, asthma, memory loss, and other chronic
Getting more D
Food is usually the best way to get vitamins. That's not so for
vitamin D. Only a few foods — salmon, tuna, sardines, milk, and
fortified cereals — can give you more than 100 IU per serving.
Sunlight is an efficient way to get more vitamin D. Many people
can make all they need by getting outside for five to 10 minutes
a day without sunscreen. Keep the exposure short because the rays
that stimulate vitamin D production are the same ones that, with
prolonged exposure, cause sunburn and skin cancer. If you live
north of a line connecting San Francisco with St. Louis and
Richmond, Virginia, don't bother doing this between November and
March — the amount of ultraviolet light hitting your body won't
be enough to generate vitamin D.
Supplements are the simplest, safest way to get vitamin D.
Multivitamins usually contain 400 IU of vitamin D. Some calcium
supplements come with added vitamin D. You can also buy vitamin D
by itself. Getting 800 to 1,000 IU from supplements is a good
It makes sense to ask your doctor to test your vitamin D level,
and to take a supplement if it is in the deficient or
insufficient range. To check your vitamin D status yourself, join
Grassroots Health (www.grassrootshealth.org), a nonprofit
organization that focuses on vitamin D. For a $40 membership fee,
you'll get information on vitamin D and a home test kit.