When it comes to losing weight, low-carb diets work. However, eliminating whole food groups from your diet, including grains and fruit, may increase your risk of nutritional deficiencies, including some of the B vitamins. If you're considering a low-carb diet to help you drop those unwanted pounds, first talk to your doctor about whether you should add a multivitamin of B-complex supplement to your regimen.
Eight water-soluble vitamins make up the B-complex, including thiamine, riboflavin, niacin, vitamin B-6, folate, vitamin B-12, pantothenic acid and biotin. While each of these vitamins plays a specific role in helping make sure your body works properly, collectively they help your body turn the food you eat into energy. They also play a role in vision, skin health and the formation of red blood cells; assist in running your nervous system; and help with appetite control.
As water-soluble vitamins, your body isn't able to store these nutrients -- with the exception of vitamin B-12 -- which means they need to be a regular part of your diet to get what you need. But, because B-vitamins are found in a variety of different foods -- vegetables, fruit, grains, beans and meat -- deficiencies are rare.
Low-Carb Diet and B-Vitamins
Cutting out foods such as grains and beans may make it hard for you to get all the B-vitamins on a low-carb diet. A 2010 study published in the Journal of the International Society of Sports Nutrition looked at some of the most popular weight-loss diet plans, including a low-carb diet, to determine if they were deficient in any nutrients. This study found that the low-carb diet, which restricted carbs to 20 grams a day, was deficient in only pantothenic acid and biotin and met 100 percent or more of the reference daily intake for the other B vitamins. The authors of this study suggest that if you're going to follow a low-carb diet, add a multivitamin supplement to ensure you get all the nutrients you need.
Signs of Deficiency
Both pantothenic acid and biotin assist in converting food into energy. Additionally, pantothenic acid helps make hormones. While beans, bread and cereal help you get these B vitamins in your diet, eggs, fresh vegetables and organ meats such as liver are also sources. Deficiency of pantothenic acid is generally seen only in cases of severe malnutrition, and symptoms include fatigue, headache, insomnia, tummy trouble and numbness of the hands and feet. Biotin deficiency is also uncommon, but if you're not getting what you need, you may feel tired, nauseated, depressed or have muscle pain.
How to Get the B-Vitamins You Need
While it seems as though you should be able to meet your B-vitamin needs on a low-carb diet, eating a variety of foods from the low-carb food list may help ensure intake is adequate. Get more pantothenic acid in your diet with no-carb sources such as lobster, pork and chicken, as well as low-carb sources such as broccoli, sunflower seeds and feta cheese, each with 1 to 2 grams of net carbs per serving. Cheddar cheese and cauliflower can help you get more biotin and have 1 and 2 grams of net carbs, respectively. Or, add eggs, liver or avocados to get both.
- Colorado State University Extension: Water-Soluble Vitamins: B-Complex and Vitamin C
- Journal of the International Society of Sports Nutrition: Prevalence of Micronutrient Deficiency in Popular Diet Plans
- Atkins: Atkins 20 Diet Plan: How Does It Work?
- Linus Pauling Institute: Pantothenic Acid
- Atkins: Carb Counter
- Linus Pauling Institute: Biotin