Conversely, hyperferritinemia was predicted by vitamin D deficiency (aOR 24.69; 95% CI 3.76-162.16; <i>p</i> = 0.001), elevated CRP (aOR 5.06; <i>p</i> = 0.014), Hb (aOR 63.23; <i>p</i> < 0.001), and inversely by grade 2 obesity (aOR 0.11; 95% CI 0.02-0.60; <i>p</i> = 0.03), confirming bidirectional CRP-ferritin associations and hyperferritinemia as an inflammation marker rather than iron overload indicator. The gene discussed is GSTM1; the disease is obesity due to melanocortin 4 receptor deficiency.