title: Stability of fat-soluble and water-soluble vitamins in artificially prepared, vitamin-enriched, lyophilized serum.
abstract: Vitamin-enriched, lyophilized serum (VES) was prepared for an inter-laboratory study to compare vitamin assays. The VES contained water-soluble vitamins (vitamin B1, vitamin B12, vitamin C, and folate), fat-soluble vitamins (vitamin A and vitamin E), and cholesterol. We performed stability studies and determined vitamin concentrations and total cholesterol in VES stored at -20 degrees C for 12 months. Our recovery of the water-soluble vitamins in reconstituted VES was 70-142%, but we recovered only 33-45% of the fat-soluble vitamins. Physicochemical properties, such as specific gravity and viscosity of the reconstituted VES did not affect manual or automated measurements of these vitamins. Vial-to-vial differences found for the VES were the same as the within-day analytical variations. There was no evidence of degradation of vitamin A, vitamin B1, vitamin B12, vitamin C, folate, and cholesterol over 12 months in VES stored at -20 degrees C. Following deproteinization, vitamin C concentration was found to be lower than when not deproteinated. Vitamin E was less stable in VES, however, and the degradation during 12 months was lower than the between-day analytical variation of the assay. Our VES is the first preparation of lyophilized control serum that contains water-soluble and fat-soluble vitamins.
authors.affiliation: Department of Laboratory Medicine, Ohashi Hospital, School of Medicine, Toho University, Tokyo, Japan. ihara-1@cam.hi-ho.ne.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ihara
authors.forename: Naotaka
authors.initials: N
authors.lastname: Hashizume
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsubayashi
authors.forename: Koichi
authors.initials: K
authors.lastname: Futaki
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yoshida
authors.forename: Naotoshi
authors.initials: N
authors.lastname: Sagawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Fujisaki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Mita
authors.forename: Akira
authors.initials: A
authors.lastname: Kadota
mesh_terms: D001205:Ascorbic Acid / Q000097:blood; D002784:Cholesterol / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D015925:Cryopreservation; D004355:Drug Stability; D005492:Folic Acid / Q000097:blood; D005612:Freeze Drying; D006801:Humans; D012016:Reference Values; D013831:Thiamine / Q000097:blood; D014801:Vitamin A / Q000097:blood; D014805:Vitamin B 12 / Q000097:blood; D014810:Vitamin E / Q000097:blood; D014815:Vitamins / Q000097:blood*
chemical_list: D014815:Vitamins; D014801:Vitamin A; D014810:Vitamin E; D005492:Folic Acid; D002784:Cholesterol; D014805:Vitamin B 12; D001205:Ascorbic Acid; D013831:Thiamine