The Influence of Iron and Zinc Supplementation on the Bioavailability of Provitamin A Carotenoids from Papaya Following Consumption of a Vitamin A-Deficient Diet.

Iron deficiency anemia, zinc and vitamin A deficiencies are serious public health problems in Cameroon, as in many developing countries. Local vegetables which are sources of provitamin A carotenoids (PACs) can be used to improve vitamin A intakes. However, traditional meals are often unable to cover zinc and iron needs.

Trace elements in foods of children from Cameroon: a focus on zinc and phytate content.

In developing countries, complementary foods are based on local cereal porridges. These foods are poor in trace elements, with a high risk of inducing micronutrient deficiencies-the primary cause of mortality in children under the age of five. Inappropriate feeding of complementary foods is the major factor creating malnutrition and micronutrients deficiencies in Cameroon children, as well as in other developing countries.

Treatment of zinc deficiency without zinc fortification.

Zinc (Zn) deficiency in animals became of interest until the 1950s. In this paper, progresses in researches on physiology of Zn deficiency in animals, phytate effect on bioavailability of Zn, and role of phytase in healing Zn deficiency of animals were reviewed. Several studies demonstrated that Zn is recycled via the pancreas; the problem of Zn deficiency was controlled by Zn homeostasis.

Validation of a column liquid chromatographic method for phytate.

A column liquid chromatographic method that uses a spectrophotometric detector for the analysis of phytate and other inositol phosphates in foodstuffs and seeds is described. It has been tested thoroughly and sent to 6 other laboratories where there was an interest in such an analytical method and the equipment was available for performing it. These samples were blinded to the individual collaborators.

Proposed phytic acid standard including a method for its analysis.

A method is described that accurately and rapidly quantifies the free and total phosphorous content of a commercially available, purified, phytic acid preparation. This allows its use as a standard for phytic acid determinations in foods. The method involves a wet ashing step followed by phosphorous measurement with a 1-amino-2-naphthol-4-sulfonic acid-molybdate reagent in a microplate reader at 660 nm.

Mechanism of zinc homeostasis.

Homeostatic equilibrium of a nutrient is characteristic of a healthy body. For zinc, phytate has been shown to alter that equilibrium in several monogastric species including man. The pancreas is an important organ in the maintenance of zinc homeostasis.

Molybdenum requirement of female rats.

Sixty 3-wk-old female Sprague-Dawley rats were randomly divided into six groups of 10 animals each. Group 1 was fed for 8 wk purified AIN-76A diet (basal diet) containing 0.025 mg molybdenum/kg diet.

Anion-exchange method for determination of phytate in foods: collaborative study.

Phytate, a naturally occurring organic compound found in plant seeds, roots, and tubers, was determined in a collaborative study using a modified anion-exchange method. Seven samples (peanut flour, oats, rice, isolated soybean protein, a vegetarian diet composite, wheat bran, and whole wheat bread), supplied as blind duplicate samples, were analyzed in triplicate by 7 collaborators. Phytate concentrations in the samples ranged from 2.

Phytate content of foods: effect on dietary zinc bioavailability.

The phytate content of several foods is presented. Published zinc values were used to calculate phytate:zinc molar ratios. These ratios can be used to estimate the relative risk of having an inadequate intake of zinc.

Effect of a chronic tryptophan dietary deficiency on the rat's sleep-wake cycle.

The sleep-wake cycle of 12 tryptophan dietary deficient rats and their non-deficient paired controls were observed for a 8:00 a.m. to 8:00 p.

Effect of washing procedures on trace-element content of hair.

A pooled sample of hair was divided and portions prepared for analysis by three washing procedures, to evaluate the effect of washing procedure on the subsequent trace-element (Zn, Cu, Mg) content. The methods selected were a detergent wash, a hexane-ethanol wash, and an acetone-ether-detergent wash. For all elements, there was a significant difference among the results after these wash procedures.

Nutritional agents which affect metabolic zinc status.

As the number of factors which affect zinc absorption and homeostasis increase, it becomes more apparent that the relative zinc status of the population cannot be estimated from the analyzed zinc content of foods. The environment of the small intestine at the time of absorption can only be estimated from the diet fed. Even then since both endogenous and exogenous factors determine the zinc absorbed, the precision of these estimations should allow for large individual variation.

Gonadal function abnormalities in sickle cell anemia. Studies in adult male patients.

Thirty-two adult patients with sickle cell anemia were evaluated endocrinologically. Secondary sex characteristics were abnormal in 29, and eunuchoidal skeletal proportions were present in all except one. The age at which different stages of pubic hair growth were attained in these patients was delayed in comparison to normals (P less than 0.

Effect of oral contraceptives on nutrients. III. Vitamins B6, B12, and folic acid.

The interactions of oral contraceptive agents (OCA's) with vitamins were studied in a large population of women. In the upper socioeconomic groups, higher incidences of abnormal clinical signs related to vitamin deficiencies were seen in OCA users than in the control subjects. Plasma pyridoxal phosphate and red cell and serum folate were lower in subjects using OCA's in the upper socioeconomic group as compared to levels in the control subjects.

Oral contraceptives, norethindrone and mestranol: effects on tissue levels of minerals.

The study involved three levels of dietary zinc (deficient, marginal, and adequate) and four hormonal conditions; namely, no steriods, norethindrone, mestranol, and norethindrone plus mestranol. The steroids were incorporated into diets and fed to 11-wk-old female Sprague-Dawley rats. After 10 wk of treatment, various tissues were excised for mineral assays by atomic-absorption spectrophotometry.

Trace elements in sickle cell disease.

Trace elements in 84 adult patients (38 men and 46 women) with sickle cell disease (SCD) were reflected in clinical and biochemical data. Height was retarded in six men and five women. Eighty percent of the SCD patients in this sample were below the 50th percentile from the normal mean for weight.

Oral contraceptives: effects on plasma insulin response to glucose and on the response to insulin and 2-deoxyglucose uptake by peripheral tissue.

Oral contraceptive steroids, norethynodrel and mestranol, were fed to 11-wk-old female Sprague-Dawley rats, in combination and in quantities proportional to those used by women for contraceptive purposes. Three experiments were performed. The first experiment, demonstrated that 10 wk of treatment, impaired the animal's glucose tolerance, but not its insulin response to glucose.

Zinc deficiency in sickle cell disease.

Clinical similarities between patients with sickle cell anemia and zinc-deficient subjects suggested a secondary zinc deficiency in sickle cell anemia. Zinc was assayed in various biological fluids and tissues by atomic absorption spectrophotometry. Zinc in the plasma, erythrocytes, and hair was decreased and urinary zinc excretion was increased in anemia patients as compared to controls.

Effect of oral contraceptive agents on nutrients: II. Vitamins.

Clinical, biochemical and nutritional data were collected from a large population of women using oral contraceptive agents. Higher incidence of abnormal clinical signs related to malnutrition were observed in the lower (B) as compared to the higher (A) socioeconomic groups, and also in the nonsupplemented groups as compared to the supplemented groups in the B subjects. As a rule the intake of oral contraceptive agent subjects of vitamin A, C, B6 and folic acid did not differ from that of the controls As expected, subjects from the supplemented groups had higher intake of vitamin A, C, B6, thiamin, riboflavin and folic acid, and A groups had higher intake of vitamin C, B6, riboflavin and folic acid.

Effect of oral contraceptive agents on nutrients: I. Minerals.

The epidemiological aspects of oral contraceptive agents on nutrient metabolism were studied in a large population of women. Incidence of clinical abnormalities, related to malnutrition, were more frequently observed in the lower (B) as compared to the higher (A) socioeconomic groups. In the A groups some clinical signs were more common in the nonsupplemented groups of subjects.