['Iron deficiency (ID) anemia leads to long-term neurodevelopmental deficits by altering iron-dependent brain metabolism. The objective of the study was to determine if ID induces metabolomic abnormalities in the cerebrospinal fluid (CSF) in the pre-anemic stage and to ascertain the aspects of abnormal brain metabolism affected.', 'Standard hematological parameters [hemoglobin (Hgb), mean corpuscular volume (MCV), transferrin (Tf) saturation, and zinc protoporphyrin/heme (ZnPP/H)] were compared at 2, 4, 6, 8, and 12 months in iron-sufficient (IS; n\u2009=\u20097) and iron-deficient (ID; n\u2009=\u20097) infant rhesus monkeys. Five CSF metabolite ratios were determined at 4, 8, and 12 months using ', 'ID infants developed ID (Tf saturation\u2009<\u200925%) by 4 months of age and all became anemic (Hgb\u2009<\u2009110\u2005g/L and MCV\u2009<\u200960\u2005fL) at 6 months. Their heme indices normalized by 12 months. Pyruvate/glutamine and phosphocreatine/creatine (PCr/Cr) ratios in CSF were lower in the ID infants by 4 months (P\u2009<\u20090.05). The PCr/Cr ratio remained lower at 8 months (P\u2009=\u20090.02). ZnPP/H, an established blood marker of pre-anemic ID, was positively correlated with the CSF citrate/glutamine ratio (marginal correlation, 0.34; P\u2009<\u20090.001; family wise error rate\u2009=\u20090.001).'] Does metabolomic analysis of CSF indicate brain metabolic impairment precedes hematological indices of anemia in the iron-deficient infant monkey?