Supplemental vitamin D is available in 2 distinct forms: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Pharmacopoeias have officially regarded these 2 forms as equivalent and interchangeable, yet this presumption of equivalence is based on studies of rickets prevention in infants conducted 70 y ago. The emergence of 25-hydroxyvitamin D as a measure of vitamin D status provides an objective, quantitative measure of the biological response to vitamin D administration. As a result, vitamin D3 has proven to be the more potent form of vitamin D in all primate species, including humans. Despite an emerging body of evidence suggesting several plausible explanations for the greater bioefficacy of vitamin D3, the form of vitamin D used in major preparations of prescriptions in North America is vitamin D2. The case that vitamin D2 should no longer be considered equivalent to vitamin D3 is based on differences in their efficacy at raising serum 25-hydroxyvitamin D, diminished binding of vitamin D2 metabolites to vitamin D binding protein in plasma, and a nonphysiologic metabolism and shorter shelf life of vitamin D2. Vitamin D2, or ergocalciferol, should not be regarded as a nutrient suitable for supplementation or fortification.
Vitamin D may be a positive regulator of AMH production in adults, and vitamin D deficiency may confound clinical decisions based on AMH. Vitamin D deficiency should be considered when serum AMH levels are obtained for diagnosis.
Maternal intake of synthetic folic acid leads to the appearance of unmetabolized folic acid in milk and, seemingly, a down-regulation of milk FBP synthesis. The impact of these changes on the bioavailability of folate in infants requires further exploration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.