Role of B12 and Homocysteine Status in Determining BMD and Bone Turnover in Young Indians

Vitamin B12 (B12) deficiency and hyperhomocysteinemia (HHcy) are independent risk factors for low bone mineral density (BMD) and fracture risk. We studied the role of HHcy and B12 deficiency in determining the peak bone mass in Indians. Randomly selected 151 healthy young adult subjects (females 100, mean age: 26 yr) underwent evaluation of dietary intake of calcium and B12; sun exposure; estimation of BMD by dual-energy X-ray absorptiometry at total hip, forearm, and lumbar spine; serum 25(OH)D3; intact parathyroid hormone; B12; homocysteine (Hcy); and bone turnover markers (BTMs) serum crosslaps, N-mid osteocalcin, and bone-specific alkaline phosphatase. Hypovitaminosis D (serum 25OHD3 < 20 ng/mL) and serum ALP level >150 IU/L were seen in 83% and 27%, respectively. Median serum B12 and Hcy levels were 140 pg/mL (interquartile range [IQR]: 72-230 pg/mL) and 18 μmol/L (IQR 14-32 μmol/L); B12 deficiency (serum B12 < 200 pg/mL) and HHcy (serum Hcy > 30 μmol/L) were present in 71% and 68%, respectively. Low BMD (Z-score <−2.0) was present in 17% of subjects. There was no significant correlation between serum Hcy, folate, B12, BTM, and BMD. BMD was predicted by height, weight, and body mass index. Young Indian healthy adults have high prevalence of hypovitaminosis D, B12 deficiency, and HHcy. There is no correlation of serum B12, folate, and Hcy status with BTMs and BMD in young, healthy, vegetarian Indian adults. Anthropometric variables predict BMD in young Indians.