Most of us know that vitamins are essential for optimal health, but when it comes to weight loss, good ol' A and C can't do the heavy lifting all on their own.
Alas, there's no magic bullet in the world of nutrition that'll help you shed those unwanted pounds. But not getting enough of certain important vitamins and minerals may actually make the challenge of weight loss that much harder. In fact, getting the right amounts of vital nutrients may boost your metabolism, which in turn can help you on your weight-loss journey.
Dropping the weight, of course, is more about how many calories you take in and how much energy you expend, but for certain people, supplements might be beneficial. When following a reduced-calorie diet, you need to focus on foods that also give your body all the vitamins necessary for good nutrition. If you think you might be deficient in nutrients and it's affecting your weight, consult your doctor to discuss the need for additional supplements.
Vitamin A and Metabolism
Most Americans don't meet the recommended intake for vitamin A, according to the Office of Dietary Supplements at the National Institutes of Health.
This fat-soluble vitamin plays an important role in the regulation of thyroid hormones, and not getting enough vitamin A in your diet is associated with reduced levels of these hormones in the body, according to a 2012 study published in the Journal of the American College of Nutrition. Thyroid hormones regulate how your body's cells use energy, which affects the rate of your metabolism. When thyroid hormone levels are too low, parts of your body slow down, and this may cause a decrease in your metabolism.
Help keep your metabolism going at a good clip by adding vitamin-A-rich foods to your diet to make sure you get the recommended daily value (DV), which is 700 micrograms for women and 900 micrograms for men, according to the Mayo Clinic. The nutrient may be toxic only in extremely large amounts over long periods of time.
There are plenty of low-calorie foods rich in the nutrient to include in your weight-loss diet. According to MyFoodData.com, some of the foods highest in vitamin A include:
- Cooked 6-ounce fillet of tuna (143 percent DV)
- One cup cooked butternut squash (127 percent DV)
- Medium-sized baked sweet potato (122 percent DV)
- One cup cooked spinach (105 percent DV)
- Medium-sized carrot (44 percent DV)
- One cup cantaloupe (33 percent DV)
Vitamin D and Weight Loss
Low levels of vitamin D are more common in obese people, according to a April 2015 review study published in Obesity Review. While the connection between vitamin D and obesity isn't clear, scientists theorize that vitamin D may play a role in regulating fat mass, which could contribute to weight gain and obesity, according to a March 2012 review study published in the International Journal of Obesity.
Indeed, a July 2018 study in the International Journal of Preventative Medicine looked at the effect of vitamin D supplementation on weight loss in a cohort of overweight and obese women and found that after six weeks of this regimen, weight, body mass index (BMI) and waist and hip circumference decreased significantly. But researchers also noted that the relationship between vitamin D and such lipid profiles as blood pressure and glycemic indexes isn't clear, so more studies are still needed.
And a January 2013 study published in Nutrition Journal found that obese participants taking calcium plus vitamin D lost more body fat on a reduced-calorie diet than those not taking any supplement.
The recommended daily dose of vitamin D is 600 international units (IU) for those ages 1 to 70, and 800 IUs for those older than 70, according to the Mayo Clinic. Overdose of the nutrient is possible, but extremely rare.
To improve your vitamin D levels, be sure to spend some time in the sun (with sunscreen, of course) and add a variety of vitamin-D-rich foods to your diet. According to MyFoodData.com, these foods include:
- Cooked 6-ounce fillet of salmon (142 percent DV)
- 16-ounce glass fortified whole milk (32 percent DV)
- One cup fortified tofu (28 percent DV)
- Hard-boiled egg (6 percent DV)
Vitamin C for Working Out
Taking more magnesium, along with antioxidant-rich vitamins like A, C and E, may help lower your BMI and waist circumference, per a December 2018 study in Nutrition Journal. And if you're not getting enough vitamin C from the foods you eat and you're working out, you may have a harder time losing fat than someone who is getting enough vitamin C.
Adults need 65 to 90 milligrams of vitamin C each day, according to the Mayo Clinic. The recommended upper limit is 2,000 milligrams; while the vitamin isn't toxic, very large doses may cause diarrhea, nausea and vomiting.
Some good dietary sources of vitamin C, according to MyFoodData.com, are one-cup servings of the following fruits and veggies:
- Red bell peppers (211 percent DV)
- Kiwifruit (185 percent DV)
- Strawberries (108 percent DV)
- Oranges (106 percent DV)
- Broccoli (90 percent DV)
- Tomatoes (61 percent DV)
B Vitamins for Energy
Because they're necessary components of your metabolism, you may think getting more B vitamins in your diet will rev up your metabolism and help you lose weight. That's not the case, however. Because they're water-soluble, your body is unable to store B vitamins, and any excess you take beyond what you need is eliminated in your urine.
Making sure you meet your B-vitamin needs, however, may help control appetite, and keep energy levels up. They're found in a variety of foods, according to MyFoodData.com, including:
- 6-ounce pork chop (96 percent DV of B1)
- One cup fortified tofu (76 percent DV of B2)
- 6-ounce cooked fillet yellowfin tuna (234 percent DV of B3)
- One cup cooked shiitake mushrooms (104 percent DV of B5)
- 6-ounce cooked fillet of wild salmon (94 percent DV of B6)
- One cup edamame (121 percent DV of B9)
- 6-ounce skirt steak (533 percent DV of B12)
- Journal of the American College of Nutrition: "The Effect of Vitamin A Supplementation on Thyroid Function in Premenopausal Women"
- Office of Dietary Supplements: "Vitamin D"
- Obesity Review: "Obesity and Vitamin D Deficiency: A Systematic Review and Meta-Analysis"
- Office of Dietary Supplements: "Vitamin A"
- Hormone Health Network: "What Is a Thyroid? How Does the Thyroid Function"
- Nutrition Journal: "Calcium Plus Vitamin D3 Supplementation Facilitated Fat Loss in Overweight and Obese College Students With Very-Low Calcium Consumption: A Randomized Controlled Trial"
- International Journal of Obesity: "The Link Between Obesity and Low Circulating 25-hydroxyvitamin D Concentrations: Considerations and Implications"
- Medical News Today: "Link Between Successful Weight Loss and Vitamin D Levels"
- Office of Dietary Supplements: "Vitamin C"
- International Journal of Preventative Medicine: "Effect of Vitamin D Supplementation on Weight Loss, Glycemic Indices, and Lipid Profile in Obese and Overweight Women: A Clinical Trial Study"
- Nutrition Journal: "Higher dietary magnesium intake is associated with lower body mass index, waist circumference and serum glucose in Mexican adults"
- Office of Dietary Supplements: "Vitamin B12"
- Mayo Clinic: "Vitamin A"
- MyFoodData.com: "Top 10 Foods High in Vitamin A"
- MyFoodData.com: "Top 10 Foods Highest in Vitamin D"
- Mayo Clinic: "Nutrition and healthy eating"
- MyFoodData.com: "High Vitamin C Foods"
- Mayo Clinic: "Vitamin D"
- Colorado State University Extension: Water-Soluble Vitamins: B-Complex and Vitamin C