The research demonstrated that the combination of vitamin D3 (VD3) and omega-3 oils therapy also showed better therapeutic effectiveness against MASLD, enhanced glucose and lipid metabolism and antioxidant and anti-inflammatory liver by improving obesity symptom and metabolic characteristics, reducing hepatic triglyceride esters, inhibiting PPARs, SREBP1, increasing insulin-induced gene 1 (INSIG1), adiponectin, AdipoR1, leptin, leptin receptor (LEPR) in HFFD model [78]. The gene discussed is INSIG1; the disease is obesity due to melanocortin 4 receptor deficiency.