SPX and vitamin D deficiency: The purpose of this randomized placebo-controlled trial was to investigate the effects of a 2,000 IU of vitamin D3 supplementation per day for 8 weeks on some serum adipokines including omentin-1 and spexin levels, inflammatory markers, lipid profile, and anthropometric parameters along with a low-calorie diet program in overweight and obese participants who had vitamin D deficiency.