Dietary Calcium and Serum 25-Hydroxyvitamin D Status in Relation to BMD Among U.S. Adults

Authors

  • Heike A Bischoff-Ferrari,

    Corresponding author
    1. Centre on Aging and Mobility, University of Zurich, Zurich, Switzerland
    2. Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts, USA
    3. Department of Rheumatology and Institute for Physical Medicine and Rehabilitation, University Hospital Zurich, Zurich, Switzerland
    • Address correspondence to: Heike A. Bischoff-Ferrari, MD, DrPA, Centre on Aging and Mobility, Department of Rheumatology and Institute of Physical Medicine, University Hospital Zurich, Gloriatrasse 25, 8091 Zurich, Switzerland
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  • Douglas P Kiel,

    1. Institute for Aging Research, Hebrew Senior Life, Harvard Medical School, Boston, Massachusetts, USA
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  • Bess Dawson-Hughes,

    1. Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts, USA
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  • John E Orav,

    1. Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts, USA
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  • Ruifeng Li,

    1. Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts, USA
    2. Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, USA
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  • Donna Spiegelman,

    1. Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts, USA
    2. Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts, USA
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  • Thomas Dietrich,

    1. Department of Oral Surgery, The School of Dentistry, University of Birmingham, Birmingham, United Kingdom
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  • Walter C Willett

    1. Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts, USA
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  • The authors state that they have no conflicts of interest.

Abstract

A higher calcium intake is still the primary recommendation for the prevention of osteoporosis, whereas vitamin D deficiency is often not addressed. To study the relative importance of dietary calcium intake and serum 25-hydroxyvitamin D [25(OH)D] status in regard to hip BMD, 4958 community-dwelling women and 5003 men ≥20 yr of age from the U.S. NHANES III population-based survey were studied. Calcium supplement users and individuals with a prior radius or hip fracture were excluded. We calculated standardized means for BMD by quartiles of sex-specific calcium intake for three 25(OH)D categories (<50, 50–74, and 75+ nM) among men and women, separately controlling for other important predictors of BMD. A higher calcium intake was significantly associated with higher BMD (p value for trend: p = 0.005) only for women with 25(OH)D status <50 nM, whereas calcium intake beyond the upper end of the lowest quartile (>566 mg/d) was not significantly associated with BMD at 25(OH)D concentrations >50 nM. Among men, there was no significant association between a higher calcium intake beyond the upper end of the lowest quartile (626 mg/d) and BMD within all 25(OH)D categories. Among both sexes, BMD increased stepwise and significantly with higher 25(OH)D concentrations (<50, 50–74, 75+ nM; p value for trend: women < 0.0001; men = 0.0001). Among men and women, 25(OH)D status seems to be the dominant predictor of BMD relative to calcium intake. Only women with 25(OH)D concentrations <50 nM seem to benefit from a higher calcium intake.

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