Vitamin D Q & A

Should children who do not drink much milk and who wear sunscreen get their blood levels of 25-vitamin D checked?

It’s not unreasonable to have your children tested if you are concerned about their being vitamin D deficient because they don’t drink milk or wear sunscreen all the time. This will help convince you and the pediatrician that the child is vitamin D deficient and requires vitamin D treatment. However, because this test is rather costly, it is recommended that children simply take 1,000 IU of vitamin D a day along with a multivitamin containing 400 IU of vitamin D a day.

Does time of day matter for recommended sun exposure?

The time of day does matter, because the angle of the sun is different. It’s very difficult to make vitamin D in the early morning or late afternoon, even I the summer, and you will make more vitamin D between noon and 2:00 P.M. than you will either make at 10:00 A.M. or 3:00 P.M.

Are there any vitamin D-stimulating lightbulbs for humans?

Vitamin D will not be produced by exposure to incandescent lightbulbs. You need to be exposed to a vitamin D-producing lamp that emits UVB radiation. Tanning beds that have fluorescent lamps also emit UVB radiation.

Does it matter whether I wear sunglasses when I expose myself to the sun?

It is recommended some face protection and sunglasses or other eye protection to reduce the risk of cataracts.

Does boiling cow’s milk destroy vitamin D?

Boiling cow’s milk will not destroy vitamin D. Vitamin D is heat stable at least up to a temperature of about 300F.

Is vitamin D better absorbed from fortified dairy or from fortified juice?

Vitamin D is equally bioavailable from fortified juice, fortified milk, and vitamin D supplement capsules.

I’ve heard that vitamin D in skim or nonfat milk isn’t as bioavailable. Is this true?

Vitamin D is just as bioavailable from skim and nonfat milk as it is from whole milk. Fat is not needed to efficiently absorb vitamin D.

Isn’t Vitamin D fat soluble? Is there a water-soluble form of vitamin D that is used to fortify orange juice and skim milk?

The vitamin D that is used in orange juice is in a micronized form that makes it water soluble. The vitamin D in skim milk is the same vitamin D that is in whole milk and is perfectly bioavailable.

Will I wash off the vitamin D I produce in my skin if I take a bath or shower within thirty minutes of being exposed to sunlight?

No. Vitamin D is made in living cells in the skin. You cannot wash it off!

USANA’s Vitamin D supplement helps to prevent vitamins D deficiency