Determination of vitamin D in foods: a review.
Determining vitamin D content in foods is difficult because in natural foods of highest vitamin D activity, and even in vitamin D-fortified foods, only small quantities are present, and many other compounds are extracted along with vitamin D that cause difficulties in purifying the extract or in the spectrophotometry or colorimetry that follows. Several physicochemical methods--such as spectrophotometric, colorimetric, thin-layer chromatographic, adsorption, partition, gas-liquid, and high-performance column chromatographic--have been tried for assay foods for vitamin D, but none of them have been accepted for official or routine use; they are time consuming and expensive, or lack the required sensitivity, precision, or accuracy. Curative biological assays, based on degree of healing of a leg bone of rats previously made rachitic, is the generally accepted method to determine vitamin D content of foods. However, that method also requires too much time and is expensive. The recently developed high-performance liquid chromatographic method may offer the most for establishing a satisfactory physicochemical method for determining vitamin D in foods. Many of the difficulties and problems in assaying foods for vitamin D are discussed.
D000818:Animals; D001681:Biological Assay / Q000379:methods; D002845:Chromatography / Q000379:methods; D002849:Chromatography, Gas / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002854:Chromatography, Paper / Q000379:methods; D002855:Chromatography, Thin Layer / Q000379:methods; D003124:Colorimetry / Q000379:methods; D005504:Food Analysis / Q000379:methods*; D005527:Food, Fortified / Q000032:analysis; D007536:Isomerism; D012015:Reference Standards; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014807:Vitamin D / Q000032:analysis*
D014807:Vitamin D