Objective: To investigate the association between plasma free amino acids (PFAAs) profile changes, vitamin D concentration and hypertension and evaluate the clinical utility of this association for nascent hypertension before the development of complications. Methods: 70 subjects were enrolled in this study; 50 of them were hypertensive (25 were with uncontrolled hypertensive and 25 were with controlled hypertensive), the other 20 subjects were healthy controls.

Results: Circulating levels of Branched chain amino acids (BCAAs);(valine, leucine, and isoleucine), Aromatic amino acids (AAAs);(phenylalanine, tyrosine, and tryptophan), homocysteine, aspartic, ornithine, asparagine and lysine were elevated significantly in both uncontrolled and controlled hypertensive subgroups in comparison with control group. On the