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Diet Diva
Diet Diva

Get advice on healthy eating, nutrition, and weight loss from expert dietitian Tara Gidus. 

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More D-Tails on Vitamin D

I have had a lot of interest and more questions about the Vitamin D post from yesterday. Hopefully the following info will answer your questions.

You can find out if you are deficient in Vitamin D by getting a blood test. Your doctor can order a 25(OH) D blood test. If your level is <15 ng/ml, you are deficient. If it is greater than 15 but less than 32, you are insufficient. Anything greater than 32 mg/ml is fine (low end of normal range).

Low Vitamin D levels are common in pregnant and breastfeeding women. One study suggests that breastfeeding women get 4,000 IU of Vitamin D daily. A supplement of 200IU of Vitamin D is recommended for breast fed babies.

Vitamin D2 is 1/3 less potent than D3, so look for D3 in supplement form or fortified into foods. It is not vegetarian (comes from fish sources).

There is some very interesting research on Vitamin D and Autism.

Sun facts:
It takes 6 times as long for dark skin to make the same amount of Vitamin D.
African Americans are much more likely to be Vitamin D deficient than Caucasians.
Older skin only has 1/4 the conversion capacity to make Vitamin D than it did when it was younger (that is why the DV for Vitamin D is higher for older people)
Fair skin can make about 10,000 IU of Vitamin D in 15-20 minutes of exposure.
A little bit of sun exposure is healthy, but put sunscreen on after 10-20 minutes, depending on how fair your skin is.

Some medications decrease Vitamin D levels:
Calcium Channel blockers, Cholestyramine, Phenytoin, Tagamet, Steroids, Heparin, Warfarin
These medications increase Vitamin D levels:
Isoniazid, thiazide diuretics, estrogen

For more information:
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Tara Gidus is a nationally recognized expert and spokesperson on nutrition and fitness.

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