Vitamin A equivalency and apparent absorption of β-carotene in ileostomy subjects using a dual-isotope dilution technique

• Published in: British journal of nutrition Vol. 103; no. 12; pp. 1836 - 1843
• Main Authors: Van Loo-Bouwman, Carolien A., Naber, Ton H. J., van Breemen, Richard B., Zhu, Dongwei, Dicke, Heleen, Siebelink, Els, Hulshof, Paul J. M., Russel, Frans G. M., Schaafsma, Gertjan, West, Clive E.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 28.06.2010
• Subjects: Adult; beta Carotene - administration & dosage; beta Carotene - metabolism; beta Carotene - pharmacokinetics; beta-carotene; Biological and medical sciences; Capsules; Cross-Over Studies; Diet; Dietary Fats - administration & dosage; dietary supplements; digestive system diseases; dual-isotope dilution technique; experimental diets; Feces - chemistry; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Humans; Ileostomy; Ileostomy subjects; ileum; Indicator Dilution Techniques; Innovative Techniques; Intestinal Absorption; Isotopes; Male; Middle Aged; nutrient balance; nutritional adequacy; nutritional intervention; patients; Stable isotopes; Vertebrates: anatomy and physiology, studies on body, several organs or systems; vitamin A; Vitamin A - analogs & derivatives; Vitamin A - analysis; Vitamin A - blood; Vitamin A equivalency; β-Carotene; Ileostomy subjects; Vitamin A equivalency; Stable isotopes; β-Carotene; Human; Ileostomy; Carotene; Vitamin; Isotope dilution; Retinol; Vertebrata; Absorption; Mammalia; Technique; Isotopes
• ISSN: 0007-1145; 1475-2662; 1475-2662
• DOI: 10.1017/S0007114509993849

The objective was to quantify the vitamin A equivalency of β-carotene in two diets using a dual-isotope dilution technique and the apparent β-carotene absorption as measured by the oral–faecal balance technique. Seventeen healthy adults with an ileostomy completed the 4-week diet-controlled, cross-over intervention study. Each subject followed both diets for 2 weeks: a diet containing vegetables low in β-carotene content with supplemental β-carotene in salad dressing oil (‘oil diet’; mean β-carotene intake 3·1 mg/d) and a diet containing vegetables and fruits high in β-carotene content (‘mixed diet’; mean β-carotene intake 7·6 mg/d). Daily each subject consumed a mean of 190 μg [13C10]β-carotene and 195 μg [13C10]retinyl palmitate in oil capsules. The vitamin A equivalency of β-carotene was calculated as the dose-corrected ratio of [13C5]retinol to [13C10]retinol in serum. Apparent absorption of β-carotene was determined with oral–faecal balance. Isotopic data quantified a vitamin A equivalency of [13C10]β-carotene in oil of 3·6:1 (95 % CI 2·8, 4·6) regardless of dietary matrices differences. The apparent absorption of (labelled and dietary) β-carotene from the ‘oil diet’ (30 %) was 1·9-fold higher than from the ‘mixed diet’ (16 %). This extrinsic labelling technique can measure precisely the vitamin A equivalency of β-carotene in oil capsules, but it does not represent the effect of different dietary matrices.