Studies of the stability and extractability of vitamin D

Radioactively labelled vitamin D 3 -4-C 14 was used as a tracer to study the in vitro degradation of vitamin D. Effects were noted of various environmental conditions such as temperature, dispersion into water, exposure to air, oxygen, and ultraviolet light, with chromatography on alumina and Fluoropak 80 being employed to evaluate destruction. Procedures which avoided potentially damaging environments are described for saponifying tissues and extracting them of vitamin D and possible metabolites. They consist basically of refluxing with KOH in methanol, extraction by organic solvents in the presence of adequate concentrations of alcohol, and partition prior to chromatography or radioactivity assay.