Children on TDF+3 TC + EFV, those with CD4 count of <200 cells/mm3 and with renal toxicity were at 4.10 (95%CI = 1.64, 6.89), 2.16(95%CI = 1.31, 4.26) and 5.94 (95%CI = 1.18, 29.89) times risk of vitamin-D in-sufficiency, respectively. The gene discussed is CD4; the disease is nephrotoxicity.