While the most effective way to lose weight is to exercise and cut calories, it might be possible to boost your weight loss by supplementing with the right vitamins. Certain vitamins in the right doses may decrease hunger, enhance weight loss and improve exercise performance. Vitamin supplementation, however, shouldn't be considered a dietary replacement for whole foods like fruits, vegetables and whole grains.
Studies have shown that supplementing with 500 milligrams of vitamin C daily may yield weight loss, improved exercise performance and enhanced calorie expenditure from fat, according to a 2005 review in the "Journal of the American College of Nutrition." Vitamin C-supplemented groups worked out more efficiently and burned more energy from fat during workouts. Dietary sources of vitamin C include citrus, bell peppers, cantaloupe, strawberries and broccoli.
Vitamin D Plus Calcium
A 2009 study in the "British Journal of Nutrition" observed that women with daily calcium intakes of less than 800 milligrams lost more weight when they supplemented with vitamin D and calcium than women who took a placebo. The supplementing group lost more body weight and fat mass and spontaneously decreased their fat intake over the 15-week study. The women with adequate calcium intake did not see the weight loss effect with supplementation. Natural sources of vitamin D include sun exposure, fatty fish like salmon and tuna and fish-liver oil. Dairy products, greens like spinach and lettuce and calcium-fortified foods are good sources of calcium.
Regular multivitamin intake may decrease appetite, making it easier to stick to your diet. Participants in a 2008 study in the "British Journal of Nutrition" who took a daily multivitamin supplement rated themselves as less hungry on an appetite scale than people who took a placebo. The group taking a multivitamin reported a reduced appetite both between meals and after meals.
Some vitamins can have unfavorable side effects when taken in excess, so it is important to know how much you need. The Institute of Medicine's tolerable upper-intake levels for adults is 2,000 milligrams of vitamin C and 100 micrograms of vitamin D daily. Because supplements aren't regulated by the Food and Drug Administration, you can't rely on product label claims for safety and efficacy. In addition, supplements can't offer the beneficial nutrient interactions provided by consuming whole foods.