L-Histidine

Tier 3 — weak evidence · Joint · Anaemia · Immune modulation

A semi-essential amino acid needed for histamine production, haemoglobin synthesis, and antioxidant defence via carnosine. A few trials show it improves fatigue in CKD and reduces joint inflammation in rheumatoid arthritis. Deficiency is rare with adequate dietary protein. Very safe at standard doses.

Dose: 1–4 g/day; most useful for CKD fatigue and RA; deficiency rare with adequate dietary protein