In older women with adequate calcium intake receiving osteoporosis medications, calcium supplements did not provide additional improvements in hip bone mineral density (BMD) or bone strength. However, a low dietary protein intake was associated with reduced skeletal benefits of antiresorptive therapy.

METHODOLOGY

• Researchers conducted a secondary analysis of the GERICO cohort in Switzerland to examine whether calcium and protein intakes affected bone changes in response to osteoporosis medications among older women with adequate calcium intake.
• The analysis included 586 women (median age, 67 years) who were followed up for a median duration of 3.5 years, of whom 101 received menopausal hormone therapy, 67 received antiresorptive drugs, and 418 did not receive any osteoporosis medications.
• Calcium and protein intakes were assessed using a validated food frequency questionnaire, and the use of calcium and vitamin D supplements was recorded at baseline and follow-up.
• Annual changes in total hip BMD, bone strength, and structural parameters were assessed using DEXA and finite element analysis.

TAKEAWAY

• The median total calcium intake (diet plus supplements) was 1503 mg/d. Overall, 71% of women met recommendations (≥ 1200 mg/d), 51% used calcium supplements, and 70% used vitamin D supplements.
• Both menopausal hormone therapy and antiresorptive therapy were associated with a less annual loss of hip areal BMD than no osteoporosis medication (P < .001 for both). Antiresorptive therapy was also associated with an attenuation of total hip strength loss (P < .001).
• Neither total calcium intake nor calcium supplementation significantly affected changes in hip BMD or bone strength. Among women consuming less than 800 mg/d of calcium, osteoporosis medications showed no apparent benefits without calcium supplementation.
• Bone-sparing effects of antiresorptive therapy on trabecular BMD and total hip strength were attenuated among women with a protein intake less than 0.8 g/kg of body weight per day vs those with a protein intake of at least 0.8 g/kg of body weight per day (P < .05 for both).

IN PRACTICE

“[The study] findings do not support the routine use of CaS [calcium supplements] in women with adequate calcium intake and highlight the importance of assessing dietary calcium intake before prescribing supplementation,” the authors wrote.

SOURCE

The study was led by Maria Papageorgiou, University of Geneva, Geneva, Switzerland. It was published online on July 17, 2026, in Osteoporosis International.

LIMITATIONS

Most women in the study had a high intake of calcium, limiting generalisability to populations with a lower calcium intake. The relatively small number of women receiving osteoporosis medications may have limited statistical power. The findings may not have applied to anabolic osteoporosis therapies, which were not evaluated.