Studies on the bioconversion of β-carotene to active vitamin A in underprivileged Guatemalan children

Bulux, Jesús; Serrano, J Quan de; Lopez, C Y; Pérez, R.; Rivera, C.; Solomons, Noel W.

doi:10.1016/s0955-2863(97)00092-2

Cited by 6 publications

(3 citation statements)

References 21 publications

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“…Although the measurement of DBS retinol is a great stride forward, several authors (14), including those associated with the present study (13,15), have pointed out the limitations of using circulating retinol concentrations as an indicator of individual vitamin A status. However, within these accepted limits, we showed that in healthy subjects DBS retinol is comparable with serum retinol.…”

Section: Discussionmentioning

confidence: 92%

Retinol concentrations in capillary dried blood spots from healthy volunteers: method validation

Craft

Bulux

Valdez

et al. 2000

The American Journal of Clinical Nutrition

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Background: Vitamin A deficiency (VAD) is a major public health problem in the developing world, leading to > 3 million eye-related problems in preschool children. Nearly 250 million children have subclinical VAD, resulting in a 23% increase in childhood mortality. Difficulties in obtaining samples to assess VAD have hampered the detection, intervention, and surveillance of VAD. The use of dried blood spots (DBS) could ameliorate many problems of vitamin A assessment. Objective: The objective of this study was to validate the use of retinol in DBS for vitamin A assessment by comparing it with venous and capillary serum retinol. Design: Venous and capillary blood specimens were obtained simultaneously from 20 healthy adult volunteers. From each blood specimen, both DBS and liquid serum were prepared (a total of 80 samples). All specimens were maintained at Ϫ70 ЊC until HPLC analysis. Results: The mean retinol concentrations in the 4 sample types were as follows: venous serum (2.02 ± 0.42 mol/L, or 58 ± 12 g/dL), capillary serum (2.06 ± 0.42 mol/L, or 59 ± 12 g/dL), venous DBS (2.06 ± 0.49 mol/L, or 59 ± 14 g/dL), and capillary DBS (2.09 ± 0.45 mol/L, or 60 ± 13 g/dL). Of the 6 possible 2-way combinations, the R 2 values ranged from 0.77 for capillary DBS versus venous DBS to 0.95 for venous serum versus capillary serum. Conclusions: DBS retinol measured by HPLC is comparable with serum retinol. Thus, it is possible to compare and combine blood retinol concentration data obtained from DBS with current and historic measurements in serum.

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Section: Discussionmentioning

confidence: 92%

Retinol concentrations in capillary dried blood spots from healthy volunteers: method validation

Craft

Bulux

Valdez

et al. 2000

The American Journal of Clinical Nutrition

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“…The resulting vitamin A is either utilized or stored at liver. Studies on rats have shown that the vitamin nutrition status influences the conversion of β‐carotene to vitamin A (Bulux, Serrano, Lopez, Perez, Rivera & Solomons 1997; Parvin & Sivakumar 2000). When dietary vitamin A is insufficient, β‐carotene 15,15′‐dioxygenase activity is elevated.…”

Section: Discussionmentioning

confidence: 99%

Effects of dietary β-carotene levels on growth and liver vitamin A concentrations of the soft-shelled turtle, Pelodiscus sinensis (Wiegmann)

Chen

Huang

2011

Aquaculture Research

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A feeding trial was conducted to evaluate the e¡ect of dietary b-carotene level on the growth and liver vitamin A concentrations in soft-shelled turtles, Pelodiscus sinensis, fed a vitamin A-free diet. Soft-shelled turtles were fed diets containing 0, 14.5, 26.5, 47.5, 87.3, 112.8 and 163.8 mg b-carotene kg À 1 for 10 weeks. Although it was not statistically signi¢cant due to high deviation within each group, mean weight gain of soft-shelled turtles fed the diet without b-carotene supplementation was the lowest among all test groups.Vitamin A concentrations in liver of turtles signi¢cantly (Po0.05) increased when dietary b-carotene level reached 47.5 mg kg À 1 indicating that soft-shelled turtles were capable of converting b-carotene to vitamin A. Analysed by regression modelling, dietary b-carotene levels for optimal growth and maximal liver vitamin A contents of juvenile soft-shelled turtles fed the vitamin A-free diets were 49.1 and 88.7 mg kg À 1 respectively.

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“…The vitamin A activity of tomato fruits is usually determined by the -carotene content (Stevens & Rick 1986). A convention has been established with respect to the efficiency of bioconversion of -carotene to retinol in which it is assumed that 6 g of dietary -carotene would yield 1 g of retinol, or one retinol equivalent (RE), on average in a healthy population (Bulux et al 1997). In the present study, the use of IAA resulted in a significantly higher (p<0.05) vitamin A activity in the tested genotypes, when compared with the control, while IBA and NAA gave no significant differences (p>0.05).…”

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confidence: 99%

Bioregulators Favourably Affect the Levels of Vitamins and Sugars in Tomato Fruit Tissues

Olaiya¹

2011

Journal of Fruit and Ornamental Plant Research

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SummaryThis study aimed to examine the influence of exogenous application of the bioregulators indole acetic acid (IAA), indole butyric acid (IBA) and naphthalene acetic acid (NAA) on the vitamin and sugar content of tomatoes. Harvested fruits of the treated tomato genotypes, namely NHLy 11, NHLy 12, NHLy 13, NHLy 15 and NHLy 16, were analysed for these parameters. Spectrophotometric analysis results showed that IAA significantly increased (p0.05) the concentrations of -carotene, vitamin A and ascorbate in all the tested genotypes, with the highest values of 707.84 g·100 g -1 fwb, 118.21 g·100 g -1 RE and 20.36 g·100 g -1 fwb, respectively, in the NHLy16 genotype. The total sugar content was not significantly affected by the treatments. It is proposed that exogenous application of these bioregulators to plant foods such as tomatoes can improve their phytonutrient concentrations, promoting better public health.

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Studies on the bioconversion of β-carotene to active vitamin A in underprivileged Guatemalan children

Cited by 6 publications

References 21 publications

Retinol concentrations in capillary dried blood spots from healthy volunteers: method validation

Retinol concentrations in capillary dried blood spots from healthy volunteers: method validation

Effects of dietary β-carotene levels on growth and liver vitamin A concentrations of the soft-shelled turtle, Pelodiscus sinensis (Wiegmann)

Bioregulators Favourably Affect the Levels of Vitamins and Sugars in Tomato Fruit Tissues

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