TNF and Osteopenia: Similarly, in the study by Jafarnejad et al. [31], all groups received 200 IU of vitamin D, and the group receiving probiotics had improvement in osteopenia markers (bone resorption and turnover), namely, bone-specific alkaline phosphatase, collagen type 1 cross-linked C-telopeptide, tumor necrosis factor α, and parathyroid hormone, but did not show an improvement in bone mineral density nor other serum indicators of osteopenia [31], compared with the group receiving placebo and vitamin D.