In April 2018 researchers from Iran published their review of the scientific literature which assessed the association between vitamin C intake and bone mineral density, risk of fractures and osteoporosis. Studies evaluating vitamin C intake in relation to bone mineral density, risk of fracture and osteoporosis were identified. An analysis of the results showed that a higher dietary vitamin C intake was associated with greater bone mineral density at both the femoral neck and lumbar spine and, in addition, a non-significant reduction in the risk of hip fracture. A further analysis revealed that a higher dietary vitamin C intake reduced the risk of osteoporosis by approximately 33 %.
Malmir H et al. Vitamin C intake in relation to bone mineral density and risk of hip fracture and osteoporosis: a systematic review and meta-analysis of observational studies. Br J Nutr. 2018 Apr;119(8):847-858.