In vivo randomized trial of three marketed milk preparations enriched with calcium and vitamins (D and K) on bone mass and bone turnover markers from biological fluids in premenopausal Caucasian women

Introduction: osteoporosis is a metabolic bone disease that leads to increased bone fragility and increased risk of fracture. Objectives: the aim of the present research was to determine the effectiveness of a diary intake of three different dairy products (250 ml) enriched with vitamins and calcium on decreasing bone mass. Methods: the present study is a comparative trial of three dairy products fortified with calcium and vitamin D, parallel, randomized, double-blind and single-center. Bone mass content (BMC), bone mass density (BMD), T-score and Z-score were measured in different locations, besides biochemical markers along 18 months in premenopausal women. Two hundred and ten volunteers from all the three groups were submitted to the same monitoring procedures, consisting on blood extraction, urine collection and energy X-ray absorptiometry (DEXA) done in the laboratory. The monitoring was carried on three times, first at month 0 (baseline), the second at month 9 (in the middle of the treatment) and, finally, at month 18 (the end of the treatment). Results: the majority of anatomical locations showed both BMC and BMD decrease ranging between 0.5% and 1.5%. The T-score and the Z-score increased in lumbar spine after the treatment with the dairy products. Moreover, the most noteworthy change on the biomarkers of bone resorption was showed by plasmatic tartrate-resistant acid phosphatase (TRAP), with and increase between 20.7% and 29.5% after the intake of the different products. Conclusions: therefore, the intake of the three dairy products improves the bone mass in lumbar spine, leading to important changes in the concentration of biomarkers of bone resorption. Especially, tartrate-resistant acid phosphatase seems to be strongly influenced by the intake of every dairy product. However, no significant differences were found between the different dairy products used in the present study. Therefore, the intake of dairy product seems to be more determinant than micronutrients supplementation.