Sufficient plasma vitamin C is related to greater bone mineral density among postmenopausal women from the Boston Puerto Rican health study

Authors: MANGANO, KELSEY - University Of Massachusetts; NOEL, SABRINA - University Of Massachusetts; DAWSON-HUGHES, BESS - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; TUCKER, KATHERINE - University Of Massachusetts

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/6/2021
Publication Date: 9/11/2021
Citation: Mangano, K.M., Noel, S.E., Dawson-Hughes, B., Tucker, K.L. 2021. Sufficient plasma vitamin C is related to greater bone mineral density among postmenopausal women from the Boston Puerto Rican health study. Journal of Nutrition. https://doi.org/10.1093/jn/nxab291.
DOI: https://doi.org/10.1093/jn/nxab291

Interpretive Summary: Vitamin C is a water-soluble vitamin that acts as a cofactor in the synthesis of collagen, a critical component of bone. This cross-sectional study evaluated associations between dietary, supplemental, and plasma vitamin C with bone mineral density (BMD) among 902 Puerto Rican adults. Plasma levels of vitamin C reflect the combined contributions of food and supplement sources of the vitamin. No associations were observed between either dietary or supplemental vitamin C and BMD of the hip; however, hip BMD was significantly higher among participants with higher compared with lower plasma levels of vitamin C. Future research is needed to determine whether plasma vitamin C status is associated with longitudinal change in BMD and reduction of fracture risk.

Technical Abstract: Background: Vitamin C may benefit bone as an antioxidant. Objectives: This cross-sectional study evaluated associations between dietary, supplemental, and plasma vitamin C with bone mineral density (BMD) among Puerto Rican adults. Methods: Diet was assessed by food-frequency questionnaire (n = 902); plasma vitamin C, measured in fasting blood (n = 809), was categorized as sufficient (>/=50 micromol/L), insufficient (20-49 micromol/L), or low (<20 micromol/L). Associations between vitamin C and BMD (measured by DXA) were tested, with false discovery rate correction for multiple comparisons, and interactions by smoking, sex, and estrogen status. Least-squares mean BMDs were compared across tertiles of diet and plasma vitamin C. Results: Participants' mean age was 59 +/- 7 y (range: 46-78 y), 72% were women, mean dietary vitamin C was 95 +/- 62 mg/d, and plasma vitamin C ranged from 1.7 to 125 micromol/L. No associations were observed between dietary vitamin C and BMD (P-value range: 0.48-0.96). BMD did not differ by vitamin C supplement use (P-value range: 0.07- 0.29). Total femur BMD was higher (P = 0.04) among plasma vitamin C-sufficient participants (mean: 1.06; 95% CI: 1.035, 1.076 g/cm2) compared with low plasma vitamin C participants (1.026; 0.999, 1.052 g/cm2) in adjusted models. Findings at the trochanter were similar (P = 0.04). Postmenopausal women without estrogen therapy, with sufficient plasma vitamin C, showed greater total femur BMD (1.004 +/- 0.014 g/cm2) compared to those with low plasma vitamin C(0.955 +/- 0.017 g/cm2; P = 0.001). Similar findings were observed at the trochanter (P < 0.001). No significant associations were observed among premenopausal women or those with estrogen therapy or men. Interactions with smoking status were not significant. Conclusions: Dietary vitamin C was not associated with BMD. Low plasma vitamin C, compared with sufficiency, was associated with lower hip BMD, particularly among postmenopausal women without estrogen therapy. Future research is needed to determine whether vitamin C status is associated with change in BMD or reduction in fracture risk.