Although we typically talk about the energy value of food in terms of calories, once you consume food, these calories are converted into a form your body can use to fuel physical activity and unconscious acts, such as breathing and keeping your heart beating. A number of vitamins and minerals are vital to this energy conversion process.
The B vitamins, including thiamin (B1), riboflavin (B2), niacin (B3), vitamin B6, pantothenic acid, and biotin, do not provide energy themselves, but rather help facilitate the production of energy in your body from the food you eat. Without B vitamins, your body wouldn’t be able to convert food into energy. Two other B vitamins, folate and vitamin B12, play important roles in making red blood cells, which transport oxygen in the body, including oxygen needed in energy production.
So does this mean taking a B-complex supplement will give you more energy for physical activity? Probably not. Once you meet your body’s B vitamin needs, which generally can be accomplished with a healthy eating plan, any extra B vitamins are excreted in the urine. It’s important, however, to eat nutrient-rich foods, especially if you’re following a calorie-restricted eating plan for weight loss where every bite counts. B-complex vitamins are found in a variety of healthy foods, such as whole grains, low-fat dairy products, green leafy vegetables, nuts, seeds, eggs, poultry, lean meat, and seafood.
The B vitamins you’re most apt to fall short on as you age are vitamins B6 and B12. Unlike some of the other B vitamins, B6 and B12 are not required to be added to refined grains and aren’t as widely available in foods. Regular exercise, especially if vigorous, increases the body’s need for vitamin B6, and adults 51 and older need more B6 than younger adults.
The ability to absorb vitamin B12 from food lessens with age, and certain medicines (such as metformin and protein pump inhibitors) can decrease absorption even more. Additionally, vitamin B12 is only found in animal-derived foods, making it more challenging for vegetarians and especially vegans (who eat no animal products) to get enough. For these groups, consuming vitamin B12-fortified cereal or B12-fortified nutritional yeast can help meet requirements. The National Academy of Medicine (formerly known as the Institute of Medicine) recommends that adults over age 50 take an oral vitamin B12 supplement, although people with poor absorption may get more benefit from vitamin B12 injections. Your doctor can assess your vitamin B12 status with a blood test.
To learn more about how your body uses vitamins and minerals and your best sources for these, purchase a copy of Eat Well and Exercise from Tufts Health and Nutrition Letter.