If you take B12 supplements and your level is high, thats almost always the explanation
Advances in ingredient stabilization, pharmaceutical-grade fermentation, encapsulation, and sustained-release technologies are reshaping formulation approaches
doi:10.1152/ajpendo.2002.282.1.E18 Mingrone G, Greco AV, Capristo E, et al
Studies measuring biochemical markers of muscle damage reveal that L-Carnitine reduces myoglobin levels immediately post-exercise (weighted mean difference: -11.55 ng/mL, p=0.04) and at 30-60 minutes (weighted mean difference: -41.09 ng/mL, p=0.001), as well as creatine kinase (CK) at 2 hours (weighted mean difference: -26.72 IU/L, p=0.02) and 24 hours (weighted mean difference: -48.72 IU/L, p=0.006) following exercise
This weight loss was not statistically different from that observed in non-carriers (19.9% weight reduction)
Assembly of collagen-binding peptide with collagen as a bioactive scaffold for osteogenesis in vitro and in vivo