Analysis of fat-soluble vitamins. XX. Determination of vitamin D in multivitamin preparations. Second collaborative study
De Vries, E.J.; Mulder, F.J.; Borsje, B.
Journal - Association of Official Analytical Chemists 61(3): 731-734
1978
ISSN/ISBN: 0004-5756 PMID: 206532 Document Number: 126787
The official first action method for determining vitamin D in multivitamin preparations was modified. The method was collaboratively studied by 7 laboratories, using 6 preparations in oil. The preparations consisted of vitamin D at various levels and at various ratios (in w/w) in vitamin A. Three samples contained cholecalciferol and 3 samples contained vitamin D3 from vitamin D3 resin. After outliers were eliminated by the Dixon test, data were analyzed and averages were compared with amounts of vitamin D known to be in each sample. For samples with vitamin D: vitamin A ratios of 1:0.5, 1:5, and 1:10, the mean vitamin D recoveries were 98.8, 94.6, and 90.7%, respectively. The method has been adopted as official final action.