Publications by authors named "Margaret Sowa"

Background: Vitamin A (VA) deficiency is a public health problem in some countries. Fortification, supplementation, and increased provitamin A consumption through biofortification are efficacious, but monitoring is needed due to risk of excessive VA intake when interventions overlap.

Objectives: Two studies in 28-36-d-old male Mongolian gerbils simulated exposure to multiple VA interventions to determine the effects of provitamin A carotenoid consumption from biofortified maize and carrots and preformed VA fortificant on status.

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Background: Liver vitamin A (VA) concentration is the gold standard for VA status, but is not routinely accessible. Adipose tissue VA concentrations, as retinol and retinyl esters, may be correlated to liver VA. α-VA (as α-retinol) is a cleavage product of α-carotene that traces postprandial VA distribution to tissues but cannot recirculate from hepatic stores, providing insight into tissue VA sources.

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Background: Biofortification of staple crops with β-carotene is a strategy to reduce vitamin A deficiency, and several varieties are available in some African countries. β-Cryptoxanthin (BCX)-enhanced maize is currently in field trials. To our knowledge, maize BCX bioavailability has not been assessed in humans.

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Biofortification of crops to enhance provitamin A carotenoids is a strategy to increase the intake where vitamin A deficiency presents a widespread problem. Heat, light, and oxygen cause isomerization and oxidation of carotenoids, reducing provitamin A activity. Understanding provitamin A retention is important for assessing efficacy of biofortified foods.

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