1van Lieshout, M, West, CE, Muhilal, , et al. (2001) Bioefficacy of β-carotene dissolved in oil studied in children in Indonesia. Am J Clin Nutr 73, 949–958.
2FAO/WHO Joint Expert Consultation (2004) Vitamin and Mineral Requirements in Human Nutrition, 2nd ed.Geneva: WHO.
3FAO/WHO Joint Expert Consultation (1988) Requirements of Vitamin A, Iron, Folate and Vitamin B12. FAO Food and Nutrition Series no. 23. Rome: FAO.
4US Institute of Medicine (2001) Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press.
5West, CE & Castenmiller, JJ (1998) Quantification of the ‘SLAMENGHI’ factors for carotenoids bioavailability and bioconversion. Int J Vitam Nutr Res 68, 371–377.
6Yeum, K-J & Russell, RM (2002) Carotenoid bioavailability and bioconversion. Annu Rev Nutr 22, 483–504.
7Castenmiller, JJM & West, CE (1998) Bioavailability and bioconversion of carotenoids. Annu Rev Nutr 18, 19–38.
8Parker, RS (1996) Absorption, metabolism, and transport of carotenoids. FASEB J 10, 542–551.
9van het Hof, KH, Gartner, C, West, CE, et al. (1998) Potential of vegetable processing to increase the delivery of carotenoids to man. Int J Vitam Nutr Res 68, 366–370.
10Castenmiller, JJ, West, CE, Linssen, JP, et al. (1999) The food matrix of spinach is a limiting factor in determining the bioavailability of β-carotene and to a lesser extent of lutein in humans. J Nutr 129, 349–355.
11de Pee, S, West, CE, Muhilal, , et al. (1995) Lack of improvement in vitamin A status with increased consumption of dark-green leafy vegetables. Lancet 346, 75–81.
12de Pee, S, West, CE, Permaesih, D, et al. (1998) Orange fruits are more effective in increasing serum concentrations of retinol and β-carotene than dark-green leafy vegetables in school children in Indonesia. Am J Clin Nutr 68, 1058–1067.
13Törrönen, R, Lehmusaho, M, Häkkinen, S, et al. (1996) Serum β-carotene response to supplementation with raw carrots, carrot juice or purified β-carotene in healthy non-smoking women. Nutr Res 16, 565–575.
14van Lieshout, M, West, CE & van Breemen, RB (2003) Isotopic tracer techniques for studying the bioavailability and bioefficacy of dietary carotenoids, particularly β-carotene, in humans: a review. Am J Clin Nutr 77, 12–28.
15Burri, BJ & Clifford, AJ (2004) Carotenoid and retinoid metabolism: insights from isotope studies. Arch Biochem Biophys 430, 110–119.
16Haskell, MJ, Jamil, KM, Hassan, F, et al. (2004) Daily consumption of Indian spinach (Basella alba) or sweet potatoes has a positive effect on total-body vitamin A stores in Bangladeshi men. Am J Clin Nutr 80, 705–714.
17Wang, Z, Yin, S, Zhoa, X, et al. (2004) β-Carotene–vitamin A equivalency in Chinese adults assessed by a isotope dilution technique. Br J Nutr 91, 121–131.
18Tang, G, Qin, J, Dolnikowski, GG, et al. (2003) Short-term (intestinal) and long-term (postintestinal) conversion of β-carotene to retinol in adults as assessed by a stable-isotope reference method. Am J Clin Nutr 78, 259–266.
19Tang, G, Qin, J, Dolnikowski, GG, et al. (2000) Vitamin A equivalence of β-carotene in a woman as determined by a stable isotope reference method. Eur J Nutr 39, 7–11.
20You, C-S, Parker, RS & Swanson, JE (2002) Bioavailability and vitamin A value of carotenes from red palm oil assessed by an extrinsic isotope reference method. Asia Pacific J Clin Nutr 11, S438–S442.
21Edwards, AJ, Nguyen, CH, You, CS, et al. (2002) α- and β-carotene from a commercial carrot puree are more bioavailable to humans than from boiled-mashed carrots, as determined using an extrinsic stable isotope reference method. J Nutr 132, 159–167.
22Feunekes, GI, van Staveren, WA, de Vries, JH, et al. (1993) Relative and biomarker-based validity of a food-frequency questionnaire estimating intake of fats and cholesterol. Am J Clin Nutr 58, 489–496.
23NEVO Foundation Bureau (2001) Dutch Food Composition Table 2001. The Hague: Dutch Nutrition Centre.
24AOAC International (1995) Official Methods of Analysis of AOAC International, 16th ed.Arlington, VA: Association of Analytical Communities.
25Osborne, DR & Voogt, P (1978) The Analysis of Nutrients in Foods. Food Science and Technology: A Series of Monographs. London: Academic Press.
26Hulshof, PJ, van Roekel-Jansen, T, van de Bovenkamp, P, et al. (2006) Variation in retinol and carotenoid content of milk and milk products in The Netherlands. J Food Comp Anal 19, 67–75.
27Hulshof, PJM, Chao, X, van de Bovenkamp, P, et al. (1997) Application of a validated method for the determination of provitamin A carotenoids in Indonesian foods of different maturity and origin. J Agric Food Chem 45, 1174–1179.
28Khan, NC, West, CE, de Pee, S, et al. (2007) The contribution of plant foods to the vitamin A supply of lactating women in Vietnam: a randomized controlled trial. Am J Clin Nutr 85, 1112–1120.
29van Lieshout, M, West, CE, van de Bovenkamp, P, et al. (2003) Extraction of carotenoids from feces, enabling the bioavailability of β-carotene to be studied in Indonesian children. J Agric Food Chem 51, 5123–5130.
30Lugtenburg, J, Creemers, AFL, Verhoeven, MA, et al. (1999) Synthesis of 13C labeled carotenoids and retinoids. Pure Appl Chem 71, 2245–2251.
31van Breemen, RB, Nikolic, D, Xu, X, et al. (1998) Development of a method for quantification of retinol and retinyl palmitate in human serum using high-performance liquid chromatography–atmospheric pressure chemical ionization–mass spectrometry. J Chromatogr A 794, 245–251.
32Wang, Y, Xu, X, van Lieshout, M, et al. (2000) A liquid chromatography–mass spectrometry method for the quantification of bioavailability and bioconversion of β-carotene in humans. Anal Chem 72, 4999–5003.
33Zhu, D, Wang, Y, Pang, Y, et al. (2006) Quantitative analyses of β-carotene and retinol in serum and feces in support of clinical bioavailability studies. Rapid Commun Mass Spectrom 20, 2427–2432.
34van Lieshout, M, West, CE, Wang, Y, et al. (2001) . In Bioavailability and Bioefficacy of β-Carotene Measured Using 13C-Labeled β-Carotene and Retinol: Studies in Indonesian Children . Wageningen University Wageningen, The Netherlands.
35Novotny, JA, Kurilich, AC, Britz, SJ, et al. (2005) Plasma appearance of labeled β-carotene, lutein, and retinol in humans after consumption of isotopically labeled kale. J Lipid Res 46, 1896–1903.
36Tang, G, Qin, J, Dolnikowski, GG, et al. (2005) Spinach or carrots can supply significant amounts of vitamin A as assessed by feeding with intrinsically deuterated vegetables. Am J Clin Nutr 82, 821–828.