SpringerLink - Journal Article
Background A long-term vegetarian diet is generally poor in vitamin B group. The lack of vitamin B12 together with vitamin B6 and folate deficiency is closely related to homocysteine metabolism. Hyperhomocysteinemia was found to be associated with increased bone turnover markers and increased fracture risk. Thus, hyperhomocysteinemia, vitamin B12 and folate deficiency may be regarded as novel risk factors for micronutrient deficiency-related osteoporosis.
Aim of the study To assess the possible impact of a vegetarian diet on bone mineral density in cohort of Slovak vegetarian women.
Methods Fasting serum glucose, albumin, calcium, phosphorous and creatinine as well as bone markers, serum vitamin B12, folate and plasma levels of total homocysteine were assessed in two nutritional groups (vegetarians vs. nonvegetarians) of apparently healthy women (age range 20–70 years). Bone mineral density of the femoral neck, trochanter, total femur and lumbar spine was measured in all subjects.
Results Vegetarians had a significantly lower weight (p < 0.05), higher PTH (p < 0.01) and homocysteine (p < 0.001). Vitamin B12 was significantly higher in nonvegetarians (p < 0.001). No differences were observed in folate levels. Univariate analysis showed significant association between homocysteine and B12 (p < 0.01), folate (p < 0.001), creatinine (p < 0.001), total proteins (p < 0.049), age (p < 0.001) and vegetarian food intake (p < 0.001). Vegetarians had a significantly lower TrFBMD (p < 0.05) and ToFBMD (p < 0.05). Age and CTx were significant predictors in all sites of measured BMD and PTH. A strong correlation between homocysteine and FNBMD (r = −0.2009, p < 0.002), TrFBMD (r = −0.1810, p < 0.004) and ToFBMD (r = −0.2225, p < 0.001) was found in all subjects.
Conclusion Homocysteine is one of the predictors of bone mineral density, and hyperhomocysteinemia is associated with lower bone mineral density. In healthy adults, homocysteine levels are dependent on age as well as on nutritional habits. Thus, elderly women on a vegetarian diet seem to be at higher risk of osteoporosis development than nonvegetarian women.