Your energy requirements go up when you exercise, so it’s not surprising that you need more calories to avoid a negative energy balance if you work out. What’s questionable is whether you need more of some vitamins and micronutrients, especially if you do long or intense workouts. One group of vitamins, in particular, have been the focus of nutritional research – the B vitamins.
B Vitamins Help with Energy Production
The B vitamins include a group of eight vitamins, each with slightly different chemical structures and functions. What they have in common is they’re involved in energy metabolism. Some of these vitamins are also vital for the production of healthy red blood cells and nervous system function. Since they are closely tied to cellular energy production and the production of ATP, you might wonder whether you need more B vitamins if you exercise. Without these important vitamins, your cells would have problems producing ATP, the source your muscles use to fuel contraction.
What does research show about exercise and B vitamins? A 2006 study found that exercise may increase the requirements for two B vitamins, riboflavin, also called vitamin B2, and vitamin B6. Another study published in the Journal of Clinical Nutrition in 2000 showed that requirements for vitamin B2, vitamin B6 , AND vitamin B1 or thiamine are higher in people who exercise, but you’re unlikely to experience problems if you’re eating a well-rounded diet. Where it could be problematic is if you’re restricting calories to lose weight or otherwise not consuming enough nutrients and calories.
Why might you need more B-vitamins if you work out? When you work out, especially at a high intensity, mitochondria have to work harder to produce ATP. To do this, mitochondria need to make more ATP-producing enzymes. This, in turn, increases a cell’s requirement for B-vitamins since the enzymes need B-vitamins to function properly. You also lose a small quantity of B-vitamins through sweat. So, if you exercise frequently in a hot environment, you may need more B-vitamins.
The studies that are out there show requirements for thiamin (vitamin B1), riboflavin (vitamin B2), and vitamin B6 seem to be most affected by exercise. Although you need folate (vitamin B9) and vitamin B12 for cellular repair, there’s no strong evidence that you need more of these vitamins if you work out as long you’re eating a healthy, balanced diet.
Can Too Little B Vitamins Impact Exercise Performance?
Researchers at the University of Oregon looked for a link between B-vitamins and exercise performance. They found those who didn’t get enough B-vitamins in their diet didn’t perform as well during high-intensity exercise. They also healed more slowly from injuries and had more difficulty building muscle. Keep in mind, this is a small study but it does raise questions about how the intake of B-vitamins impacts exercise performance, especially when you consider the role some B-vitamins play in energy metabolism.
Are You Getting Enough?
If you eat a varied diet and consume enough calories, you’re probably getting enough B vitamins. On the other hand, if you’re restricting calories to lose weight or are eating a vegan diet, your risk of deficiency goes up. Vegans are at especially high risk for vitamin B12 deficiency since plant-based foods don’t naturally contain vitamin B12.
A vitamin B12 deficiency can have serious consequences. You need it for building red blood cells and for healthy nerve and brain function. People who don’t get enough can experience permanent brain and nerve damage. People who are deficient usually have problems absorbing vitamin B12, although long-term vegans who don’t supplement with B12 are also at risk. Absorption problems are more common in older people due to low stomach acid and in those who have a condition called pernicious anemia.
Deficiency of a variety of B vitamins, especially thiamine, is more common in alcoholics. Alcohol reduces the absorption of thiamine from the small intestinal tract.
Sources of B-Vitamins that May Impact Exercise Performance
The three B vitamins most closely linked with exercise performance based on the research is vitamin B1 (thiamine), vitamin B2(riboflavin), and vitamin B6. Here are some of the best sources of each:
. Vitamin B1 – Found in small quantities in many foods. Pork is one of the best sources, although packaged foods are frequently fortified with vitamin B1.
. Vitamin B2 – meat, milk products, fortified whole grains
. Vitamin B6 – meat, fish, poultry, potatoes, some fruits.
As you can see, most of the B vitamins that potentially impact exercise performance are concentrated in meat and dairy foods. If you eat a plant-based diet, you’ll need to make an extra effort to include sources of B vitamins in your diet, or, in some cases, take a supplement.
The Bottom Line
B vitamins play an essential role in energy metabolism. You may need more of some B vitamins, including vitamin B1, B2, and B6 if you do high-intensity exercise, especially if you exercise in a hot environment where you sweat a lot. As long as you’re eating a nutrient-dense, varied diet, you probably don’t need to worry about getting more B vitamins.
On the other hand, if you’re a vegan or vegetarian, be aware that you may not be getting enough of some B vitamins. Also, whether you exercise or not, talk to your healthcare provider about vitamin B12 since your risk of deficiency is higher. Most importantly, don’t sacrifice nutrition by cutting calories too much, especially if you’re physically active. Exercise places additional demands on your body and you need adequate nutrients to meet the demand and to perform your best. Fuel up properly!
Int J Sport Nutr Exerc Metab. 2006 Oct;16(5):453-84.
Am J Clin Nutr. 2000 Aug;72(2 Suppl):598S-606S.
Oregon State University Extension Service. “B-vitamins play an important role in athletic performance”
Institute of Medicine (US) Committee on Military Nutrition Research; Marriott BM, editor. Washington (DC): National Academies Press (US); 1993.
Nutrition and Diet Therapy. Seventh Edition. (2008) Thomson and Wadsworth
Related Articles By Cathe: