|Richarson, Christine - University Of California|
|Rogers, Tara - University Of California|
|Demmer, Elieke - University Of California|
|Garrod, Majorie - Consultant|
|Van Loan, Marta|
Submitted to: Journal of Nutrition and Food Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/17/2017
Publication Date: 3/31/2017
Citation: Richarson, C.E., Rogers, T.S., Demmer, E., Garrod, M.G., Gertz, E.R., Van Loan, M.D. 2017. Contribution of magnesium and micronutrients to bone metabolism in post menopausal women consuming a fixed amount of calcium and vitamin d: an exploratory study . Journal of Nutrition and Food Sciences. 2:001-008.
Interpretive Summary: Osteoporosis is a major public health issue with 50% of postmenopausal women experiencing an osteoporosis fracture in her life time. These fractures can lead to other health consequences including disability, pneumonia and death. Therefore to better understand the contribution of nutrients, other than calcium and vitamin D, to bone health is important. We studied the dietary intake of 12 postmenopausal women during the course of an 18 week study. The diet for the women had a fixed amount of calcium and vitamin D, but no other dietary restriction was imposed. During the 18 weeks we evaluated 56 food diaries specifically for other nutrients important to bone: protein, zinc, sodium, magnesium, potassium, etc. In our analysis we found that a fixed intake of calcium and vitamin D that bone resorption was significantly reduced while intake of potassium, sodium, magnesium and folate were significant predictors of bone formation prior to the start of the study. During the calcium and vitamin D intervention zinc, potassium, sodium, B-12 and protein predicted improved bone formation. This study demonstrates the importance of other nutrients to bone health most of which can be obtained by the inclusion of dairy products daily in the diet of postmenopausal women.
Technical Abstract: Most research relating diet to bone health and osteoporosis has involved the roles of calcium, vitamin D,and their synergistic activity; however, other nutrients have been shown to also play pivotal roles. In the present study, associations between magnesium and other micronutrients on bone metabolism were investigated in twelve postmenopausal women in a randomized controlled trial. Subjects received a labeling dose of 100nCi 41Ca and started a 180 day equilibration period for the isotope to stabilize in the skeleton followed by three 6-week phases, which included a calcium/vitamin D supplementation period and a dairy period in a cross-over method, with a six week wash-out period in between. Both interventions demonstrated positive effects on bone metabolism, as shown by a significant decrease in carboxy-terminal collagen crosslinks (CTx) a marker of bone resorption. Regression models demonstrated that Zn, K, Na, Mg, and folate were significant predictors of bone formation (bone alkaline phosphatase, BAP) at baseline while the Ca/Mg and Ca/Zn ratios explained baseline resorption. Following interventions Zn, K, Na, Mg, B-12 and protein were predictors on BAP and Ca/Zn and Ca/Mg ratios remained significant predictors of resorption. In conclusion, while calcium and vitamin D are important to bone metabolism, other micronutrients also make a significant contribution to bone health and need further investigation to better understand the mechanism of action and how the quality of the diet affects bone metabolism.