β-Cryptoxanthin from supplements or carotenoid-enhanced maize maintains liver vitamin A in Mongolian gerbils (Meriones unguiculatus) better than or equal to β-carotene supplements

Abstract

Maize with enhanced provitamin A carotenoids (biofortified), accomplished through conventional plant breeding, maintains vitamin A (VA) status in Mongolian gerbils (Meriones unguiculatus). Two studies in gerbils compared the VA value of b-cryptoxanthin with b-carotene. Study 1 (n 47) examined oil supplements and study 2 (n 46) used maize with enhanced b-cryptoxanthin and b-carotene. After 4 weeks' depletion, seven or six gerbils were killed; remaining gerbils were placed into weight-matched groups of 10. In study 1, daily supplements were cottonseed oil, and 35, 35 or 17·5 nmol VA (retinyl acetate), b-cryptoxanthin or b-carotene, respectively, for 3 weeks. In study 2, one group of gerbils was fed a 50 % biofortified maize diet which contained 2·9 nmol b-cryptoxanthin and 3·2 nmol b-carotene/g feed. Other groups were given equivalent b-carotene or VA supplements based on prior-day intake from the biofortified maize or oil only for 4 weeks. In study 1, liver retinol was higher in the VA (0·74 (SD 0·11) mmol) and b-cryptoxanthin (0·65 (SD 0·10) mmol) groups than in the b-carotene (0·49 (SD 0·13) mmol) and control (0·41 (SD 0·16) mmol) groups (P,0·05). In study 2, the VA (1·17 (SD 0·19) mmol) and maize (0·71 (SD 0·18) mmol) groups had higher liver retinol than the control (0·42 (SD 0·16) mmol) group (P, 0·05), whereas the b-carotene (0·57 (SD 0·21) mmol) group did not. Bioconversion factors (i.e. 2·74 mg b-cryptoxanthin and 2·4 mg b-carotene equivalents in maize to 1 mg retinol) were lower than the Institute of Medicine values. Carotenoids comprise an important class of phytochemicals in plants. Among more than 600 naturally occurring carotenoids, a-carotene, b-carotene and b-cryptoxanthin are the major provitamin A carotenoids present in foods. The bioconversion rate of b-cryptoxanthin, a mono-hydroxylated xanthophyll found in tangerine, papaya, apricot, and red pepper, to vitamin A (VA) is not known. Efforts to biofortify foods such as carrots and maize (i.e. increase the provitamin A content) have focused on b-carotene (1,2) ; however, some varieties of biofortified maize contain substantial amounts of b-cryptoxanthin (2) . In order to direct maize-breeding efforts, it is important to know the contribution of b-cryptoxanthin to VA status.The structure of b-cryptoxanthin implies that one molecule will yield one molecule of retinol (Fig. 1). Unlike the hydrocarbons, a-and b-carotene, b-cryptoxanthin is bipolar because of the electronegative oxygen in the hydroxyl group on one side of the molecule. The effects of this bipolar structure on incorporation into mixed micelles and its impact on bioavailability have not been studied. As proposed by the Institute of Medicine (IOM) (3) , the bioconversion of dietary b-cryptoxanthin to VA is reported to be the same as a-carotene, i.e. 24 mg b-cryptoxanthin or a-carotene to 1 mg retinol (3) . This is twice the amount of b-carotene, i.e. 12 mg b-carotene to 1 mg retinol, and is based on the theoretical yield from the chemical structure. The IOM bioconversion factors were calcu...

Carotenoid Retention of Biofortified Provitamin A Maize (Zea mays L.) after Zambian Traditional Methods of Milling, Cooking and Storage

“…2 However, animal studies have shown that β-cryptoxanthin is absorbed and stored in many tissues 16 and it maintains the vitamin A status of gerbils as efficiently or better than β-carotene. 17 Most of the yellow maize grown and consumed throughout the world has less than 2.0 μg/g DW of provitamin A carotenoids in kernels. 2 The first wave of biofortified maize grown in Zambia contained 7.5 to 10.3 μg/g DW BCE and higher levels of β-cryptoxanthin, which is as efficient as β-carotene as a source of vitamin A.…”

Usefulness of Vitamin A Isotope Methods for Status Assessment: From Deficiency through Excess

“…The beauty of breeding staple crops with provitamin A carotenoids is that the body will offer a line of protection from hypervitaminosis A due to the regulatory mechanisms in place during the bioconversion of provitamin A carotenoids to retinol [41]. Maize has been biofortifi ed with both β-carotene and β-cryptoxanthin [42,43]. On a mass basis, these two provitamin A carotenoids have similar bioeffi cacy [42,43].…”

“…Maize has been biofortifi ed with both β-carotene and β-cryptoxanthin [42,43]. On a mass basis, these two provitamin A carotenoids have similar bioeffi cacy [42,43]. Biofortifi ed maize genotypes have been fed to Zambian children with quick adaptation periods [44,45].…”

A Cameroonian Traditional Cake (<i>Komba</i>) Prepared Using Yellow Maize Reduce Vitamin A Deficiency in Lactating Mothers

“…Yellow maize has been shown to be rich in beta carotenes, a primary precursor of vitamin A [11]. This food crop has been found to have a high potential to maintain the hepatic reserves of retinol in animals [12] [13]. Supplementation with the yellow variety of maize, a staple in this region of Cameroon can go a long way to alleviate VAD.…”