The TT genotype of the C677T polymorphism in MTHFR has been associated with CVD (Morita et al. 1998), dementia (Kageyama et al. 2008), osteoporosis (Gjesdal et al. 2007), depression (Bottiglieri 2005) and kidney diseases (Sakamoto et al. 2015). Here, MTHFR is linked to osteoporosis.