Are Vegetarians Healthier?

Why are you limiting the vitamin D source to sunlight?

The whole point is moot in regards to the main discussion of is a vegetarian diet healthier? Eating a diet of vegetables will provide plenty of vitamin D for you body which you acknowledge albeit saying they are possibly not utilized as well. So why are you listing a sunlight myth as evidence in proving a vegetarian diet is not optimal? I'm not sure it's even a well accepted myth, rather seems to just be one more bit of ammo Weston A Price misuses.

The latest and seemingly most comprehensive study comparing D2 and D3 concludes that in fact vitamin D2 is just as effective. Below I quote Dr Michael Holick who explains the latest study to date.

" To determine whether vitamin D2 was as effective as vitamin D3 in maintaining circulating blood levels of 25-hydroxyvitamin D, a study was conducted whereby healthy adults received either 1,000 IU of vitamin D2 or 1,000 IU of vitamin D3 in a capsule once a day in the winter for 11 weeks. In addition, one group received a placebo capsule and one group received a capsule that contained 500 IU of vitamin D2 and 500 IU of vitamin D3 daily for 11 weeks. Blood levels of both 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 were determined by state of the art method using liquid chromatography tandem mass spectroscopy. Holick et al, (Vitamin D2 is as effective as vitamin D3 in maintaining circulating concentrations of 25-hydroxyvitamin D, J Clin Endocrinol Metab 93:677-681, 2008;) reported that the blood levels of 25-hydroxvitamin D rose to the same degree in the healthy adults who took either 1,000 IU of vitamin D2 a day or 1,000 IU of vitamin D3 a day for 11 weeks. The group that received vitamin D2 also had their blood level of 25-hydroxyvitamin D3 measured. There was no significant drop in the blood level of 25-hydroxyvitamin D3. To determine whether the mixture of vitamin D2 with vitamin D3 would alter the blood levels of 25-hydroxyvitamin D, the adults who received 500 units of vitamin D2 with 500 units of vitamin D3 also raised their total blood levels of 25-hydroxyvitamin D3 in an almost an identical manner as the adults who received 1,000 IU of vitamin D2 or 1,000 IU of vitamin D3 a day for 11 weeks. The authors concluded that ingesting 1,000 IU of vitamin D2 or 1,000 IU of vitamin D3 a day during the winter (at a time when sun exposure had no influence on blood levels of 25-hydroxyvitamin D) that both vitamin D2 and vitamin D3 were equally effective in maintaining the blood levels of 25-hydroxyvitamin D. Furthermore, vitamin D2 did not have a negative influence on serum levels of 25-hydroxyvitamin D3. Adults who took 500 units of vitamin D2 with 500 units of vitamin D3 had similar increases in their blood levels of 25-hydroxyvitamin D suggesting that vitamin D2 taken with vitamin D3 does not have any negative influence on the metabolism of vitamin D3.

The authors reviewed in their Conclusion several studies that had previously reported that vitamin D2 was as biologically effective as vitamin D3 in both pregnant women and in healthy adults. This study confirms these observations and adds to the body of scientific literature demonstrating that at least when healthy adults take 1,000 IU of vitamin D2, they can be assured that it is as effective as taking 1,000 IU of vitamin D3 "