The proposed study is designed to determine the maximum benefit to bone mineral density of the hip that can be derived from increasing intakes of calcium and vitamin D in an elderly population to levels which are expected to be both nutritionally optimal and safe. Average intakes of vitamin D and calcium in those over age 65 are only half to two-thirds of recommended amounts. This study will define what proportion of age-related bone loss is attributable to inadequate intakes of these two nutrients and will provide reference data against which the effectiveness of more invasive or experimental interventions can be assessed. Compared to hormonal and drug therapies, nutritional intervention has few expected side effects, is inexpensive, and can be appropriate for a wide cross-section of the elderly population. The proposed study will determine the effect of daily supplementation with 500 mg of elemental calcium (as citrate malate) plus 700 IU of cholecalciferol on changes in bone mineral density of the hip in 424 men and women who are 65 or older. A three-year randomized, double-blind trial is proposed. One half of the participants will be assigned to the treatment group (calcium+D) and the other half to a placebo group. The two groups will be balanced for sex and age decade. Bone mineral density of the femoral neck, lateral spine and whole body will be measured semi-annually by dual-energy absorptiometry. Other data to be collected include results of blood and urine tests and measures of dietary calcium, dietary vitamin D, grip strength, physical activity, sunlight exposure and travel to other latitudes. Information about smoking and alcohol use, travel, medication use, ethnic background and the occurrence of falls will be obtained by interview. Measurement intervals are planned so that seasonal variation in rates of bone loss and other variables will not confound the analyses or interpretation. In addition to providing an estimate of the maximum benefit to bone mineral density that can be derived from the provision of adequate calcium and vitamin D, this study will examine seasonal patterns of bone loss, overall and seasonal relationships between bone loss and calcium regulating hormones, and influences of biochemical, physiological and behavioral factors on the occurrence of falls.

National Institute of Health (NIH)
National Institute on Aging (NIA)
Research Project--Cooperative Agreements (U01)
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Biological and Clinical Aging Review Committee (BCA)
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Tufts University
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United States
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Dawson-Hughes, Bess; Harris, Susan S; Ceglia, Lisa et al. (2014) Effect of supplemental vitamin D and calcium on serum sclerostin levels. Eur J Endocrinol 170:645-50
Dawson-Hughes, Bess; Harris, Susan S; Ceglia, Lisa et al. (2014) Serum sclerostin levels vary with season. J Clin Endocrinol Metab 99:E149-52
Sempos, Christopher T; Durazo-Arvizu, Ramon A; Dawson-Hughes, Bess et al. (2013) Is there a reverse J-shaped association between 25-hydroxyvitamin D and all-cause mortality? Results from the U.S. nationally representative NHANES. J Clin Endocrinol Metab 98:3001-9
Niramitmahapanya, Sathit; Harris, Susan S; Dawson-Hughes, Bess (2011) Type of dietary fat is associated with the 25-hydroxyvitamin D3 increment in response to vitamin D supplementation. J Clin Endocrinol Metab 96:3170-4
Durazo-Arvizu, Ramón A; Dawson-Hughes, Bess; Sempos, Christopher T et al. (2010) Three-phase model harmonizes estimates of the maximal suppression of parathyroid hormone by 25-hydroxyvitamin D in persons 65 years of age and older. J Nutr 140:595-9
Pitroda, Arpita Patel; Harris, Susan S; Dawson-Hughes, Bess (2009) The association of adiposity with parathyroid hormone in healthy older adults. Endocrine 36:218-23
Pittas, Anastassios G; Harris, Susan S; Eliades, Myrto et al. (2009) Association between serum osteocalcin and markers of metabolic phenotype. J Clin Endocrinol Metab 94:827-32
Bischoff-Ferrari, H A; Orav, E J; Dawson-Hughes, B (2008) Additive benefit of higher testosterone levels and vitamin D plus calcium supplementation in regard to fall risk reduction among older men and women. Osteoporos Int 19:1307-14
Blum, Miriam; Dallal, Gerard E; Dawson-Hughes, Bess (2008) Body size and serum 25 hydroxy vitamin D response to oral supplements in healthy older adults. J Am Coll Nutr 27:274-9
Dawson-Hughes, Bess; Harris, Susan S; Ceglia, Lisa (2008) Alkaline diets favor lean tissue mass in older adults. Am J Clin Nutr 87:662-5

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