In diverse HIV-infected populations, Vitamin D insufficiency and deficiency are associated with HIV disease progression, and virological failure after antiretroviral therapy initiation.[45] Recent randomized clinical trials indicated that vitamin D supplementation improved CD4 recovery and vitamin D repletion suggesting potential benefit on immunologic recovery during cART.[48,49]. This evidence concerns the gene CD4 and hyperinsulinemic hypoglycemia, familial, 4.