You Ask, I Answer/In The News: Vitamin D requirements
Posted Oct 14 2008 4:06am
I read today that the recommended amount of vitamin D has doubled due to a new study.
I thought most people get enough of it.
How much vitamin D do we get from dairy as compared to being out in the sun?
--Hemi Via the blog
The issue of Vitamin D requirements being too low has been a hot topic in the nutrition field for years.
According to current recommendations, children and adults up to the age of 50 should get at least 200 International Units, adults 50 to 71 years of age should aim for 400 IUs, and anyone above the age of 71 should be taking in 600.
The new guidelines you are referring to bump up the 200 IUs figure to 400 IUs.
Even so, many researchers think everyone should aim for 1,000 IUs a day!
The best source of Vitamin D is the sun, but this can get complicated.
After all, we get this vitamin from exposure to UVB rays, which are not as powerful in winter months and have a harder time getting through on cloud-covered days.
Additionally, the massive use of moisturizers and creams that block out UVB rays prevents many people from absorbing a good deal of "solar powered" vitamin D.
Some fortified foods (i.e.: cereals, soy milks, and dairy milk) provide vitamin D, while others (tuna, salmon, and... ugh, cod liver oil) do so naturally.
Despite this, it can be very difficult to meet the Vitamin D recommended intakes without some sort of supplementation.
For example, a cup of fortified dairy milk provides a quarter of a day's worth of Vitamin D (using 400 IUs as the goal).
Not bad, but unless you're planning on downing four glasses of milk a day, you will come up short.
Keep in mind, too, that many dairy products (like yogurt, cottage cheese, and ice cream) are NOT fortified with vitamin D.
Going back to the sun, the general recommendation is that 30 minutes of exposure to sunlight twice a week provides sufficient levels vitamin D.
Interestingly, research studies earlier this year concluded that individuals living in countries near the equator tend to have higher vitamin D levels than their counterparts to the North and South.