Vitamin D2 vs D3

[swtiepie711]

---

Members do not see this ad.

On p144 of the Biochemistry Kaplan notes, it was said that milk contains Vitamin D2 derived from irradiated plant ergocalciferol.

However, in First Aid and on most of the websites I can find, it says that milk has Vitamin D3 in it, not D2.

On one hand, I think "who cares?" - on the other hand, it means bypassing a step (i.e. Vitamin D3 must be converted to 23-hydroxycholecalciferol in the liver) - so does anyone know where I can find out which is for sure or if this even matters? TIA.

 

[facetguy]

Milk can contain either D2 or D3. Both need to be hydroxylated in the liver.

Here's a paper on D2 vs. D3: http://www.ajcn.org/cgi/content/full/84/4/694

Regarding effectiveness in raising blood 25-OH-D levels, D3 is almost always considered the more effective form, although a recent paper did dispute this:
http://www.ncbi.nlm.nih.gov/pubmed/...nkpos=3&log$=relatedarticles&logdbfrom=pubmed

Good luck.