HIF1A and obesity due to melanocortin 4 receptor deficiency: Vitamin C (VC, ascorbic acid) has been shown to prevent obesity by the followings (54): (a) regulating lipid accumulation in adipocytes through direct action on differentiation mechanisms or by modulating motor behavior, (b) inhibiting lipolysis and thus reducing the export of fatty acids to the system, (c) inhibiting glucocorticoid production, and (d) directly interfering with adipose cell-macrophage interactions, (e) scavenging of reactive oxygen species, and (f) possible inhibition of the HIF-1a pathway.