Vitamin A and zinc supplementation of preschool children.

Objective: To determine whether supplementation of vitamin A and/or zinc (Zn) improved serum levels of these nutrients and/or height and weight gains in preschool children, 22 to 66 months, living in Belize, Central America.

Methods: Subjects received either Zn, vitamin A, Zn and vitamin A or a placebo, (70 mg Zn and/or 3030 RE vitamin A, once per week) for 6 months in a 2x2 factorial design. Forty-three children, from a population of 104 prescreened, completed the study; they were selected, prior to treatment, for low/marginal serum concentrations of these micronutrients.

Serum carotenoid concentrations and their reproducibility in children in Belize.

Suggestions that carotenoid-containing foods are beneficial in maintaining health have led to several studies of circulating carotenoid concentrations of adults. Because few data are available for children, we report serum carotenoid concentrations of 493 children in Belize. Carotenoid concentrations were determined as part of a survey of vitamin A status of children, most between 65 and 89 mo of age.

Reproducibility of relative dose response (RDR) test and serum retinol and retinyl ester concentrations in children after a 2-week interval.

Objective: Reproducibility of the relative dose response test (RDR), a test designed to measure vitamin A status, was tested in 23 Belizean children, 5-8 years after 2-week interval during which no treatment was given.

Methods: As required for the RDR test, serum retinol concentrations were determined before and 5 hours after an oral dose of vitamin A. An RDR score > 14% was used as the criterion of inadequate vitamin A status.

Comparison of methods of assessing vitamin A status in children.

Objective: A study of children (2-8 years; n = 613) in Belize, Central America, was conducted to determine what proportion of the children might be at risk of vitamin A (vit A) deficiency. The data provide an opportunity to compare results of three methods of assessing vit A status in a population which was not severely malnourished. Serum retinyl ester concentrations were also determined; their relevance to one of the tests, the relative dose response (RDR) test, is discussed.

Sodium and potassium intakes and excretions of normal men consuming sodium chloride or a 1:1 mixture of sodium and potassium chlorides.

Two groups of 10 healthy young men were matched on the basis of their free-choice consumptions of regular table salt. For 28 days they were then fed carefully controlled low-sodium foods. One group was permitted free-choice seasoning of these foods with regular table salt, the other with a 1:1 mixture of sodium and potassium chlorides.

Aluminum absorption and distribution: effect of parathyroid hormone.

In rats, gastrointestinal aluminum absorption and tissue distribution were altered by parathyroid hormone; the resultant tissue concentrations were similar to those observed in dialysis patients with a fatal encephalopathy. In dialysis patients, serum aluminum and endogenous parathyroid hormone concentrations are significantly correlated. These data suggest that aluminum toxicity in dialysis patients results from oral aluminum ingestion in the presence of hyperparathyroidism.