Bone Turnover Response to Changes in Calcium Intake Is Altered in Girls and Adult Women in Families with Histories of Osteoporosis

Abstract

Heredity and environmental factors contribute to the development of osteoporosis. Because calcium is the major mineral in bone and adolescence is a key period in bone acquisition, we hypothesized that bone turnover would be less responsive to alterations in dietary calcium intake in both girls and adult women from families with histories of osteoporosis. To address this issue, we studied calcium kinetics in the maternal grandmother (age range 56-81 years), mother (age range 32-47 years), and granddaughter (age range 8-15 years) in 10 multigenerational families. In five families, the mother and/or grandmother had osteoporosis (bone mineral density > 2 SD below the age-specific mean). To examine both active and passive calcium absorption, families consumed low-(279 ؎ 64 mg/day) and high-(1580 ؎ 385) calcium diets for 10 days prior to administration of oral ( 46 Ca) and intravenous ( 42 Ca) stable isotopes. Using repeated measures analysis of variance, fractional calcium absorption, true calcium absorption, bone calcium deposition, and the balance in bone calcium turnover were all significantly affected by diet ( p < 0.01). Females from nonosteoporotic families had decreased bone calcium resorption with little change in bone calcium deposition during the high-calcium study. In contrast, girls and adult women from osteoporotic families had increased both bone calcium deposition and resorption during the high-calcium period, leading to a less positive balance in bone calcium turnover. A significant interaction between bone status and diet was found for bone calcium resorption ( p < 0.05) and approached significance for bone calcium deposition ( p < 0.07), effects which were independent of generation. We conclude that girls and women from osteoporotic families have a significantly altered bone turnover response to acute changes in calcium intake. (J Bone Miner Res 1998;13:491-499)

Calcium balance in 1–4-y-old children

“…This is Ȃ1.5 SD above the value for estrogen-replete premenopausal women (ie, Ȃ30 Ȁ 10%) at the same calcium intake (18,19). Thus, although calcium's absorptive efficiency has been shown to be greater in adolescents than in adults, it appears that, at low calcium intakes, the same is true for infants and young children (20,21).…”

Sodium and Bone Health: Impact of Moderately High and Low Salt Intakes on Calcium Metabolism in Postmenopausal Women

“…A marginally negative bone balance is observed in postmenopausal women because of the dominance of bone resorption over bone formation, but large interindividual differences have been reported in women adapted to low and high calcium intakes (21) . The particular strength of the data presented here is the randomized cross‐over study design that used four very‐well‐controlled diets that provided different intakes of calcium and sodium within the range that is commonly observed in Western‐style diets.…”

Stable Isotopes of Minerals as Metabolic Tracers in Human Nutrition Research

“…The double isotope technique has been used for studies of calcium absorption in girls (44,45), as well as girls and women from families with histories of osteoporosis (46), postpartum women during and after lactation (47), and infants (48). The infant study, in addition to IV and oral doses of calcium isotopes, included IV and oral doses of zinc, making is possible to determine the FA of both calcium and zinc.…”