When you're trying to shed pounds, you want to make sure to cover your nutritional bases. That means meeting the recommended daily intakes for all the essential vitamins. If you're already meeting your needs, taking extra vitamins won't help you lose weight -- only a reduced-calorie diet and exercise will help you achieve that. But if you have a deficiency, correcting it with vitamins might help with some aspects of weight loss. Consult with your doctor before taking supplements or if you suspect you have a nutrient deficiency.
If you're deficient in vitamin D, you may find it more difficult to lose weight successfully on a low-calorie diet, say researchers of a study from the University of Minnesota. Presenting their results at The Endocrine Society's 91st Annual Meeting, the researchers showed that baseline vitamin D levels before calorie restriction predicted weight-loss results in 38 overweight people involved in the 11-week study. The lower the vitamin D level at the start of the study, the less weight the participant lost. The researchers suggested that a vitamin D supplement could be a useful addition to a weight-loss diet but said that more studies are needed. Note that these findings haven't gone through a peer review yet. You need 15 milligrams of vitamin D daily -- moderate sun exposure, dairy products and fatty fish can help you meet this goal.
Weight-loss clinics market vitamin B-12 shots to boost energy and metabolism, but if you're not deficient in B-12, there's no evidence to support that those shots will do anything but empty your wallet. However, if your doctor diagnoses you with B-12 deficiency, you'll want to get your levels back up to normal as soon as possible. B-12 is one of eight B vitamins, all of which play a role in healthy metabolism. In addition, a symptom of B-12 deficiency is fatigue, which can be debilitating and prevent you from getting the regular exercise you need to lose weight. Aim to consume 2.4 micrograms of B-12 each day. Meat, fish, eggs, dairy and fortified cereal all contribute to your intake.
A water-soluble vitamin crucial for the healthy maintenance of skin, bones and teeth and for wound healing, vitamin C may also play a role in efficient fat burning. A review published in the Journal of the American College of Nutrition in 2005 reported that individuals with vitamin C deficiency may find it more challenging to lose body fat. The review notes that individuals who have adequate vitamin C levels are able to burn 30 percent more calories during an exercise session than those with a deficiency. You need a small amount of vitamin C each day -- 75 milligrams for women and 90 milligrams for men. Eat at least one serving of fruits or vegetables at each meal to meet your needs.
Who's at Risk and What You Need
If you eat a balanced diet, you're likely getting the vitamins you need, but that can be difficult when you're dieting, says the Harvard Health Publications website. If you don't get enough sun exposure -- vitamin D is found in few foods but is manufactured by your skin when exposed to sunlight -- you may not be getting enough vitamin D. If you're a vegetarian or you have a digestive disorder that inhibits nutrient absorption, you may not be getting enough B-12. Vitamin C deficiency is less common but can still result from an inadequate diet.
Is a Multivitamin the Answer?
Some experts recommend taking a multivitamin to cover all your bases, and one study, published in the International Journal of Obesity in February 2010, showed that obese women who took a multivitamin for 26 weeks had significantly lower body weight, body mass index and fat mass than those who didn't. Still, other experts, including Harvard Medical School nutrition educator Dr. Helen Delichatsios, say multivitamins are unnecessary and ineffective and that dieters can get most of what they need by eating a low-calorie, nutrient-rich diet that includes nutrient-rich foods such as leafy greens, salmon, eggs, nuts and seeds, beans and sweet potatoes.