Vitamin D
A lack of vitamin D is probably the most common deficiency in northern countries such as Canada, or most of the US. Three recent studies indicate that, when compared to a placebo, a vitamin D supplement can decrease your fat weight or waist measurement [1 2 3].
In one of the studies, 77 overweight or obese women received either a supplement of 1000 units of vitamin D, or a placebo, every day for 3 months. Those who took the vitamin D supplement decreased their body fat by 2,7 kg (6 pounds) – significantly more than the placebo group, who hardly decreased their fat weight at all.