Zinc, vitamin B-6, and other nutrients in pregnant women attending prenatal clinics in Mexico.

Biochemical measurements and 24-h dietary recalls were conducted early (18.9 +/- 5.9 wk) and late (35.1 +/- 2.0 wk) in pregnancy in women attending clinics in Montemorelos, Mexico. Mean weight gain per week (0.4 +/- 0.2 kg) and birth weight (3381 +/- 456 g) were normal. Intakes tended to decline during pregnancy and declined significantly for zinc (p less than 0.05) and vitamin B-6 (p less than 0.03). Mean Zn intake late in pregnancy was low (7.8 +/- 3.3 mg/d). Various supplements were taken but none contained Zn. During pregnancy mean plasma Zn levels fell (p less than 0.001) and late in pregnancy 57% of the women had values suggestive of poor Zn status (less than or equal to 8.1 mumol/L). These data indicate that Zn intakes of approximately 8 mg/d will not maintain plasma Zn levels in late pregnancy. Erythrocyte glutamic-pyruvic transaminase (EGPT) index and the index of diamine oxidase (DAO), a vitamin B-6-requiring enzyme of placental origin, were correlated suggesting that DAO index may be useful in evaluating vitamin B-6 status in pregnancy.

PIP: Biochemical measurements and 24 hour dietary recalls were conducted early (18.9 +0- 5.9 weeks) and late (35.1 +or- 2.0 weeks) in pregnancy in women attending clinics in Montemorelos, Mexico. Mean weight gain per week (0.4 +or- 0.2 kg) and birth weight (3381 +or- 456 grams) were normal. Intakes tended to decline during pregnancy and declined significantly for zinc (p 0.05) and vitamin B-6 (p 0.03). Mean zinc intake late in pregnancy was low (7.8 +or- 3.3 mg/d). Various supplements were taken but none contained zinc. During pregnancy mean plasma zinc levels fell (p 0.001) and late in pregnancy 57% of the women had values suggestive of poor zinc status (or= 8.1 micromoles/liter). These data indicate that zinc intakes of approximately 8 mg/d will not maintain plasma zinc levels in late pregnancy. Erythrocyte glutamic-pyruvic transaminase (EGPT) index and the index of diamine oxidase (DAO), a vitamin B-6-requiring enzyme of placental origin, were correlated suggesting that DAO index may be useful in evaluating vitamin B-6 status in pregnancy.

Vitamin B-6 nutriture and plasma diamine oxidase activity in pregnant Hispanic teenagers.

Vitamin B-6 status was assessed by measuring erythrocyte glutamic-pyruvic transaminase (EGPT) indices in 122 pregnant Hispanic teenagers. Seventeen percent were vitamin B-6 deficient (EGPT indices greater than 1.25) at the initial interview (first or second trimester). A daily supplement of 5 mg vitamin B-6, beginning at initial interview, did not reduce prevalence of vitamin B-6 deficiency at final interview (third trimester). No association was found between EGPT indices greater than 1.25 and the outcome of pregnancy. The activity of diamine oxidase (DAO), a vitamin B-6-dependent enzyme produced by the placental decidua, was measured in maternal plasma. At initial and final interviews, plasma-DAO activity was increased by in vitro addition of pyridoxal-5'-phosphate. The activity in early pregnancy was positively associated with dietary vitamin B-6 intake and was lower in teenagers with EGPT indices greater than 1.25 at the final interview. Findings suggest that plasma-DAO activity is influenced by vitamin B-6 status.