in the summertime sun (sunscreen-free, with
arms and legs exposed) can produce about
10,000 IUs of the vitamin.
However, dark-skinned individuals and the
elderly produce less vitamin D 3 , and those
who live in the Northern Hemisphere may not
be able to produce enough vitamin D in the
winter, as the sun may not get high enough in
the sky for its UV-B rays to penetrate the
atmosphere. Which means that many of us are
walking around chronically deficient in
vitamin D 3 and at higher risk for conditions
like osteoporosis, heart disease, and certain
types of cancer.
Luckily, supplementation with vitamin D 3is quite effective at replenishing and
maintaining stores in the body. Of course,
some is good, but more is not better. While
you can’t overdose on D 3 if you’re getting it
from the sun, some research suggests that
supplementing with more than 10,000 IUs a