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Calcium Absorption Among Racially Diverse Pregnant Women
Author(s) -
Lesser Mary N. R.,
Nguyen Leyna,
King Janet C.,
O'Brien Kimberly O.,
Fung Ellen B.
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.45.1
Subject(s) - medicine , pregnancy , calcium , calcium metabolism , excretion , bone resorption , endocrinology , gestation , fetus , absorption (acoustics) , vitamin d and neurology , physiology , biology , genetics , physics , acoustics
Longitudinal studies of calcium metabolism during pregnancy (PG) have shown that maternal calcium (Ca) absorption increases progressively from the first to the third trimester to meet the needs of the developing fetus. This increase in calcium absorption is directly related to maternal Ca intake. However, even with this increase in absorption, maternal and fetal needs may not be met in women with chronically low Ca intakes (<500 mg/day). Low Ca intakes are not uncommon among women in the USA and may result in maternal bone mobilization. Studies of Ca intake and absorption among racially diverse pregnant women are limited. Thus, this cross‐sectional study was done to determine the effect of racial differences on Ca absorption during the third trimester of pregnancy. Forty women, 10 each from four racial groups (African‐American (AA), Asian, Caucasian, Latina) were recruited between 30–36 weeks gestation. The following outcomes were measured: Ca intake from validated FFQ, Ca absorption, 24 hour urinary Ca excretion, 25OH vitamin D, and bone resorption as assessed by C‐terminal telopeptide (CTx). Ca absorption was measured from a standardized breakfast meal providing 330 mg Ca using the dual stable isotope technique (44Ca oral & 42Ca IV). To date, 34 women have completed the study (6 AA, 8 Asian, 10 Caucasian, 10 Latina) and are presented herein. Preliminary results show that of the 4 groups, only Latina and AA women met the pregnancy Ca RDA. Fasting serum Ca averaged 10.4 ± 0.6 mg/dL in the group as a whole, and it was not associated with CTx or race (r=0.0019, p=NS). Ca absorption ranged from 28.6–80.6% in the whole group of 34 women, and it was not associated with the habitual Ca intake. However, there is an interaction between race, Ca intake and Ca absorption, suggesting that women of different race absorb Ca differently based on Ca intake. 25OH vitamin D was significantly higher (p=0.053) in Caucasian women (29.9 ± 6.5 ng/mL) compared to Asian women (21.3 ± 6.0 ng/mL), and it was inversely related to Ca absorption (p=0.044). 24 hour urinary Ca excretion averaged 163.6 ± 85.5 ug/mL in the whole group; it did not differ by racial group, but it was positively related to Ca absorption (p=0.016). Our preliminary results suggest that in this group of racially diverse women, Ca metabolism is highly variable (intake, absorption, and excretion), which has a larger influence on Ca metabolism parameters than any potential effect due to race. Support or Funding Information Supported by USDA #2009‐02925