Free CMWL Shortbread Bar (Everyone’s Fav!), when you call or reply. Why CMWL? Reason#10: Vitamin D Deficiency. Vitamin D receptors are found everywhere in the body, including the brain and fat cells. Fat cells send signals to your body via a hormone called, leptin, which regulates your hunger levels. The more leptin your body produces, the less hunger you will feel. When your body has sufficient levels of D, it releases more of the appetite-suppressing hormone. Conversely, a lack of Vitamin D lowers the amount of leptin and disrupts the body’s ability to control hunger.