I understand that, in winter time, when we do not have enough exposure to sunlight it makes sense to supplement with vitamin D. I found out that there are two types, vitamin d2 and vitamin d3. Although d2 seems less expensive, I am not sure whether their health effects are the same, or at least similar, I mean whether both types have protective effects for our health. What do you say, is there much difference between d2 and d3 or they are more or less the same?
Vitamin D2 = ergocalciferol, produced by fungus (including mushrooms that grow in a sunny area)
Vitamin D3 = cholecalciferol, produced by animals including humans. This is the form you want.
There is no reason at all to take D2. D3 is cheap enough and probably works better, negating any cost savings with D2.
Good question, and maybe someone can get into the extensive details, I haven't read up about it in detail.
I can tell you with absolute certainty that if you want to supplement vitamin D, only bother with D3. The body doesn't do well at absorbing D2 so it is mostly useless.
As you kind of eluded to in your question, you're best of getting your vitamin D mostly from sunlight. There is approximately around 3,000 different variations of D3, when you supplement you might get 2-3. When you convert it from ultraviolet B waves you're getting some of the whole lot.
Currently winter here in Australia and due to a stress fracture I currently have I'm meticulously supplementing with a few things to promote absolute maximum bone health/healing, including D3.
I think once I'm healed and summer has rolled around again I'll run the experiment of getting vit D levels tested pre-summer, get lots of sun over summer, get tested again going into autumn, then during winter, then spring to see if I can buffer enough vit D during summer to last me the winter. This way I can avoid supplementation and it would be similar to how our non-equatorial ancestors would have maintained good vit D levels.
Oh.. so the short answer, use Vit D3. :)
Is vitamin D deficient good for fetuses? 2 Answers
Are my Vitamin D levels causing my acne? 7 Answers