Re: Natural versus synthetic
The conclusion of the paper is that " ingestion of 1000 IU vitamin D2 or vitamin D3 for 11 weeks was effective in raising total serum concentrations of 25(OH)D"
Vitamin D2 250 capsules 1,000 IU each $35.95 [250,000 IU)
Vitamin D3 240 capsules 5,000 IU each $17.15 [1,200,000 IU]
Purchasing D2 might have a bit of an impact on the effectiveness of the contents of my wallet!