Search PubMed⌕ Search

Biomedical subjects

M B Andon

Publications and source records attributed to M B Andon.

26 records · Page 2Linked to original sources

Vitamin B-6 intakes of lactating women: analyzed vs calculated values.

Results of our study suggest that calculation of vitamin B-6 content of diets using a current database can provide a reasonably good estimation of the vitamin B-6 intakes of a population of lactating women. Our study also demonstrates that the mean vitamin B-6 intake of this group of lactating women 2 months after they had given birth, who were not using vitamin B-6 supplements, was 1.45 mg, which is less than 70% of the RDA. However, on the basis of guidelines for the assessment of vitamin B-6 status using dietary vitamin B-6:protein ratio (15,20), the women appeared to be consuming adequate amounts of vitamin B-6.

Adolescent↗

Dietary intake of total and glycosylated vitamin B-6 and the vitamin B-6 nutritional status of unsupplemented lactating women and their infants.

The mean dietary intakes of total and glycosylated vitamin B-6, determined from analysis of 3-d diet composites collected from 30 lactating women, were 8.63 +/- 4.04 and 1.33 +/- 0.85 mumol/d (mean +/- SD), respectively. A comparison of linear regression models that either included or excluded dietary glycosylated vitamin B-6 content indicates that the intake of glycosylated vitamin B-6 had little, if any, effect upon maternal plasma pyridoxal 5'-phosphate concentration and maternal urinary excretion of total vitamin B-6 and 4-pyridoxic acid. On the basis of guidelines from the literature for evaluating biochemical indices of vitamin B-6 nutriture, the women appeared to be consuming adequate amounts of the vitamin. The mean breast-milk concentrations of total and glycosylated vitamin B-6 were 733 and 18 nmol/L, respectively. Infant plasma pyridoxal 5'-phosphate concentration was 54 +/- 44 nmol/L (mean +/- SD) and all infants had lengths and weights appropriate for age.

Adult↗

Nutritional and medical status of lactating women and their infants in the Kathmandu valley of Nepal.

In six villages in the Kathmandu valley of Nepal, an intensive health and nutrition study was conducted on 26 lactating women and their 2--6-month-old infants. Analysis of 24-h duplicate diet composites indicated that the mothers were consuming approximately 2100 kcal energy/d. The diets contained approximately 62 g protein (11.6% of the calories), 392 g carbohydrate (73.3% of the calories), and 20.9 g fat (8.6% of the calories) and a mean of 24 g neutral detergent fiber. Although anthropometric measurements indicated that the mothers had mild protein malnutrition and inadequate energy reserves, their infants exhibited low-normal weight and length for age. All the mothers had hepatitis A antibodies; 92% had tropical eosinophilia, indicating intestinal parasites; 16% had cheilosis and angular stomatitis, indicating a possible B-vitamin deficiency; and 8% had elevated urinary nitrite, indicating urinary tract infection. There were no unusual physical findings on the infants. Although the children appeared healthy, the mothers showed evidence of multiple infections and possible nutrient deficiencies.

Adolescent↗

Copper, iron, zinc, and selenium dietary intake and status of Nepalese lactating women and their breast-fed infants.

The dietary intake of copper, iron, zinc, and selenium of 26 Nepalese lactating mothers was estimated from chemical analysis of 24-h food and beverage composites. Fasting blood and milk samples were obtained from the mothers and blood samples were obtained from the infants. The Nepalese mothers consumed significantly more Cu, significantly less Fe and Se, and similar amounts of Zn as compared with American lactating women. Blood Fe status indices and plasma concentrations of Cu, Zn, and Se were lower in the Nepalese mothers than in the American mothers. These lower values may in part be related to the high neutral detergent fiber and phytate content of the Nepalese diet, which could make these minerals less available for absorption. The high exposure to infections in Nepal may also depress Fe status indices and plasma Zn concentrations. The lower dietary Se intake of the Nepalese mothers was reflected in lower milk concentrations.

Beverages↗

Calcium and magnesium dietary intakes and plasma and milk concentrations of Nepalese lactating women.

Dietary calcium and magnesium intakes of 26 Nepalese lactating women were determined from analysis of 24-h duplicate food and beverage composites. In addition, blood, urine, and milk samples were collected. The mean Ca intake of these Nepalese mothers, 482 +/- 249 mg/d, was less than half that of American lactating women yet the Ca concentration of the milk was similar for the two groups of women. The Nepalese mothers appeared to maintain milk Ca concentrations by an increase in bone resorption as demonstrated by an elevated excretion of hydroxyproline. The Nepalese women had a mean Mg intake of 353 +/- 28 mg/d. Two locally available foods considered special for lactating women, jwano and gundruk, were examined for nutrient content and found to contain high concentrations of Ca and Mg. Increased consumption of these locally grown foods could add substantially to the Ca and Mg intakes of these lactating women.

Bone Resorption↗

A comparison of plasma pyridoxal 5'-phosphate concentrations in capillary (finger prick) and venous blood.

The purpose of our study was to investigate the validity of using capillary blood plasma to estimate the pyridoxal 5'-phosphate (PLP) concentration of venous blood plasma. To accommodate the small volumes of capillary blood usually obtained, we modified the experimental conditions of the L-tyrosine apodecarboxylase (TDC) assay for PLP by increasing both the specific activity of 14C-tyrosine and the reaction incubation time. Plasma PLP concentrations determined by the TDC assay and the micro-modified TDC assay were highly correlated (r = 0.995, p = 4.0 X 10(-6)). Using the micro-modified TDC assay, we observed no significant difference between the plasma PLP concentrations of venous and capillary (finger prick) blood from 10 healthy adults. Thus, capillary blood plasma can be used to estimate the PLP concentration of venous blood plasma. This observation will aid in verifying data concerning the vitamin B-6 status assessment of individuals as determined by capillary blood plasma PLP concentrations.

Adult↗

Pyridoxal phosphate concentrations determined postmortem as an indication of antemortem vitamin B-6 status.

In anticipation of studies relating vitamin B-6 status determined at autopsy to known pathologic causes of death, the postmortem stability of pyridoxal phosphate (PLP) in the plasma, skeletal muscle, and liver of pigs was assessed. Concentrations of plasma K, Mg, Na, and Ca also were examined for postmortem stability using the pig as an experimental model. At 1 hr after death, the mean plasma PLP concentration was essentially unchanged from that observed prior to death. Thereafter, plasma PLP concentration increased with increasing postmortem time interval and was 2.3 times greater than initial by 6 hr postmortem and 7.6 times greater than initial by 12 hr postmortem (P less than 0.01). Skeletal muscle and liver PLP content were 35% lower than initial by 6 hr postmortem (P less than 0.01). Plasma K and Mg were significantly higher by 1 hr postmortem (P less than 0.01) while plasma Na concentration was significantly lower by 1 hr postmortem (P less than 0.01). Plasma Ca concentration was not significantly different at any measured time point. Knowledge of the postmortem time interval appears to be required in order to evaluate the antemortem vitamin B-6 status using pyridoxal phosphate values derived from autopsy samples.

Animals↗

Nutritionally relevant supplementation of vitamin B6 in lactating women: effect on plasma prolactin.

Pharmacologic doses of vitamin B6 administered to lactating women have been reported to suppress plasma prolactin. As a result, some physicians have recommended restriction of vitamin B6 intake for lactating women. In the present investigation, 20 lactating women were given supplemental doses of vitamin B6, 0.5 to 4.0 mg/d, beginning 24 hours after delivery. Plasma prolactin, plasma pyridoxal phosphate, and breast milk total vitamin B6 concentrations were determined during the first 9 months postpartum. Women receiving the supplement of 4.0 mg compared with 0.5 mg of vitamin B6 per day had significantly higher plasma pyridoxal phosphate (P less than .01) and breast milk total vitamin B6 concentrations (P less than .05) beginning at 1 month postpartum and continuing through the duration of the study. Plasma prolactin concentrations were not significantly different between the two groups. The percentage of all women, regardless of treatment, in whom lactation persisted at 1 and 2 weeks and 1, 3, 6, and 9 months were 100%, 100%, 100%, 90%, 80%, and 65%, respectively. All women who ceased to lactate during the study reported doing so by choice. Nutritionally relevant doses of vitamin B6 elevated plasma pyridoxal phosphate and breast milk total vitamin B6 concentrations of lactating women without reducing plasma prolactin concentration or halting lactation.

Adult↗