Calcium absorption and kinetics are similar in 7- and 8-year-old Mexican-American and Caucasian girls despite hormonal differences

J Nutr. 1999 Mar;129(3):666-71. doi: 10.1093/jn/129.3.666.

Abstract

To assess the possibility of ethnic differences in mineral metabolism in prepubertal children, we compared measures of calcium metabolism in 7- and 8-y-old Mexican-American (MA) and non-Hispanic Caucasian (CAU) girls (n = 38) living in southeastern Texas. We found similar fractional calcium absorption, urinary calcium excretion, calcium kinetic values and total-body bone mineral content in the MA and CAU girls. In contrast, parathyroid hormone (PTH) concentrations were greater in MA girls (4.01 +/- 0.47 vs. 1. 96 +/- 0.50 pmol/L, P = 0.005) than in CAU girls. Serum 25-hydroxyvitamin D concentrations were lower in MA girls (68.9 +/- 7.7 vs. 109.4 +/- 8.4 nmol/L, P = 0.001) than in CAU girls, but 1, 25-dihydroxyvitamin D concentrations did not differ between groups. Seasonal variability was seen for 25-hydroxyvitamin D concentrations in girls of both ethnic groups, but values in all of the girls were >30 nmol/L (12 ng/mL). We conclude the following: 1) greater PTH levels in MA girls than CAU girls are present without evidence of vitamin D deficiency; and 2) differences in 25-hydroxyvitamin D and PTH concentrations between MA and CAU girls do not have a large effect on calcium absorption, excretion or bone calcium kinetics. These data do not provide evidence for adjusting dietary recommendations for mineral or vitamin D intake by MA girls.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Absorption
  • Body Composition
  • Bone Density
  • Calcifediol / blood*
  • Calcitriol / blood
  • Calcium / metabolism*
  • Calcium / urine
  • Child
  • Female
  • Follicle Stimulating Hormone / blood
  • Hispanic Americans*
  • Humans
  • Kinetics
  • Luteinizing Hormone / blood
  • Mexico / ethnology
  • Parathyroid Hormone / blood
  • Seasons
  • Texas

Substances

  • Parathyroid Hormone
  • Luteinizing Hormone
  • Follicle Stimulating Hormone
  • Calcitriol
  • Calcifediol
  • Calcium