Similarly, serum complement C3 (p < 0.001), along with C1q (p < 0.05) and C2 (p < 0.001), were all low in the anorexia nervosa group of another study (n = 14), but with normal serum levels of C4, C5, and C6 when compared to the controls [67]. Here, C3 is linked to anorexia nervosa.