Vitamin D is available in 2 distinct forms, ergocalciferol (vitamin
D
2) and cholecalciferol (vitamin D3) These are officially regarded
as equivalent and interchangeable (
1-
3). Although sunshine exposure
and fish consumption provide vitamin D in the form of D
3, a
different bioactive, plant-derived form of vitamin D, named
vitamin D
2, was produced in the early 1920s through ultraviolet
exposure of foods. This process was patented and licensed to
pharmaceutical companies, which led to the development of a
medicinal preparation of vitamin D
2 called Viosterol (
4). Because
antirachitic bioassays were used to establish "rat units" for
vitamin D (ie, the amount of vitamin D required for recalcification
of the epiphyseal end of tibiae in rats), early workers found
it extremely difficult to distinguish between the specific biological
value of the 2 forms.
To this day, the major preparations of vitamin D for prescription use in North America are in the form of vitamin D2, not vitamin D3. Multivitamins may contain either vitamin D2 or vitamin D3, but most companies are now reformulating their products to contain vitamin D in the D3 form. Here, we present the case that vitamin D2 should no longer be considered equivalent to vitamin D3 and that vitamin D2, or ergocalciferol, should not be regarded as a nutrient suitable for supplementation or fortification.
Some people who take NSAIDS may find that if they take Vitamin D [any type] supplements that they don't work........if they take GERD medication.