Most people should be able to get their vitamin D requirements
met through calculated sunlight exposure. The truth is, however,
that our world still has nearly one billion people who are
vitamin D deficient, so we’re not getting enough of this
sunshine vitamin. There are various reasons for not getting
enough vitamin D. A person’s occupation, age, sunscreen use,
geographic location, the time of day, a person’s melanin content
and even smog can directly affect vitamin D levels. In fact,
when those who are 70+ in age are exposed to the same amount of
sunlight as a young adult, they produce 30% less vitamin D than
a younger person. Similarly, those with dark skin need 5-10
times longer sun exposure to make the same amount of vitamin D
as those with lighter skin do. Sunscreens may be one of the
biggest culprits of all, however, because SPF 8 and above
sunscreens can reduce vitamin D production by 95%. Where you
live can have a lot to do with how much vitamin D you can get
from the sun, too. If you live north of a