B Vitamins Don't "Give You Energy"—So What Do They Actually Do?
We call them the “energy vitamins.” But B vitamins don't actually give you energy.
Sounds like I'm starting off with a contradiction, right?
After all, B-complex supplements have been associated with energy for decades. They're often one of the first things people are told to reach for when they're feeling run down, and you'll frequently hear that B vitamins help “boost energy.”
There's just one catch: B vitamins contain no energy at all. They have no calories. They aren't stimulants. And taking a B-complex doesn't give your body a shot of energy in the way caffeine can temporarily make you feel more alert.
So why are B vitamins so closely associated with energy? Because there's an important difference between having fuel and being able to use it.
Your Food Contains Energy. Your Cells Have to Unlock It.
The carbohydrates, fats and proteins we eat contain chemical energy. But your cells can't simply take a bite of your lunch and start running on it.
Food has to be digested into smaller components such as glucose, fatty acids and amino acids. Those molecules then enter an elaborate series of metabolic pathways that eventually allow your cells to produce ATP (adenosine triphosphate).
ATP is often called the body's “energy currency” because it's the form of energy our cells can actually use.
Your brain needs it to think. Your digestive tract needs it to move food. Your cells need it to build, repair and maintain themselves. Even while you're sleeping, your cells are busily producing and using ATP.
This is where B vitamins enter the story.
B Vitamins Help Turn Food Into Usable Energy
Most B vitamins function as—or become parts of—coenzymes.
Coenzymes help enzymes carry out chemical reactions. And many of the reactions involved in breaking down nutrients and producing cellular energy simply can't proceed normally without them.
Food provides the fuel. Your metabolic machinery converts that fuel into usable energy. B vitamins are required for that machinery to work.
Why Can Low B Vitamins Make You Feel Tired?
B vitamins don't contain energy, but they are required for normal energy metabolism and healthy red blood cell production.
Vitamin B12 or folate deficiency, for example, can lead to megaloblastic anemia, which commonly causes fatigue and weakness.
Severe thiamine deficiency interferes with normal carbohydrate metabolism and can have serious neurological and cardiovascular consequences.
So correcting a deficiency can make a profound difference in how someone feels.
Meet the B Family
There are eight recognized B vitamins, and while they're commonly grouped together, each has its own jobs.
B1 — Thiamine
Thiamine plays a particularly important role in carbohydrate metabolism, helping the body process glucose through pathways involved in energy production. Organs with high energy demands—including the brain and heart—are particularly dependent on normal thiamine metabolism.
B2 — Riboflavin
Riboflavin is converted into two important coenzymes called FMN and FAD. You don't need to remember the names. What's interesting is what they do.
They're involved in numerous oxidation-reduction reactions, including reactions within the mitochondria—the tiny structures inside most of our cells where much of our ATP is produced.
And if you've ever wondered why taking a B-complex can turn your urine an almost impressively fluorescent shade of yellow? That's riboflavin. Riboflavin itself is naturally yellow and fluorescent. Excess amounts can be excreted in urine, producing that unmistakable colour.
B3 — Niacin
Niacin gives us NAD and NADP, two coenzymes involved in hundreds of reactions throughout the body.
NAD in particular has received enormous attention in recent years because of its involvement in cellular energy metabolism, DNA repair and other fundamental cellular processes. Our bodies use forms of vitamin B3 as precursors to make NAD.
B5 — Pantothenic Acid
Pantothenic acid forms part of coenzyme A, or CoA.
CoA sits at an important crossroads in metabolism, helping the body process carbohydrates, fats and proteins.
One of its best-known forms, acetyl-CoA, feeds into the Krebs cycle—the series of reactions many of us vaguely remember from biology class and promptly tried to forget! The important part is that B5 helps your body access energy from the food you eat.
B6 — Pyridoxine
Vitamin B6 participates in more than 100 enzyme reactions, many involving amino acids—the building blocks of protein.
It also plays roles in glycogen metabolism, neurotransmitter production, hemoglobin formation and immune function. So while B6 belongs in the energy conversation, its résumé extends considerably beyond it.
B7 — Biotin
Most people know biotin as the “hair vitamin", but that's only a small part of its story.
Biotin acts as a coenzyme for enzymes involved in the metabolism of fatty acids, glucose and amino acids.
B9 — Folate
Folate is essential for DNA synthesis and cell division, making it particularly important when cells are rapidly growing and dividing. Its importance during pregnancy is well known because adequate folate before and during early pregnancy helps reduce the risk of neural tube defects.
It also works closely with vitamin B12 in one-carbon metabolism and contributes to normal red blood cell formation.
B12 — Cobalamin
Vitamin B12 has some especially interesting biology.
It plays essential roles in DNA synthesis, red blood cell formation and normal neurological function, and works closely with folate in several metabolic pathways.
Unlike most B vitamins, B12 is stored in significant amounts in the body—primarily in the liver. Those stores can sometimes last for years.
B12 has an unusually complicated absorption process. From food, it must be freed from protein, bind to intrinsic factor in the stomach and then be absorbed farther down the digestive tract. That's one reason B12 is so commonly sold as a sublingual supplement: dissolving it under the tongue is intended to allow some absorption through the tissues of the mouth rather than relying entirely on the digestive pathway.
Who Should Pay Particular Attention to B Vitamins?
Most people can obtain B vitamins by eating a balanced, healthy diet, but needs and intake aren't identical for everyone.
B-vitamin status may deserve particular attention in people who:
- follow restrictive diets
- eat little or no animal food, particularly in the case of B12
- are older and may absorb B12 less efficiently
- have certain gastrointestinal conditions or surgeries that affect absorption
- take medications that can affect particular B vitamins
- consume substantial amounts of alcohol
- are pregnant or planning pregnancy, when folate requirements are especially important
- are experiencing severe or chronic stress
It's also important to point out that persistent, significant fatigue can have many possible causes—from inadequate sleep, poor diet, and/or chronic stress to iron deficiency, thyroid disorders, infection, pharmaceutical side-effects and numerous undiagnosed medical conditions. If you're unusually or persistently tired, it's worth investigating with your primary care provider.
Energy Is a Team Sport
As important as B vitamins are, they don't produce energy by themselves.
Cellular energy production also depends on adequate calories, protein, minerals, oxygen delivery, mitochondrial function and dozens of enzymes and other nutrients.
Then there's everything outside the nutrient equation: sleep, physical activity, stress, hormones, hydration and overall health. Everything is interconnected, and choosing the right supplement isn't always straightforward.
Our knowledgeable team is here to help you understand your options and make informed choices based on your individual needs. Contact us or visit any Optimum Health location to speak with us.
YOU Make the Energy
Every second of every day, your cells are carrying out an extraordinary network of chemical reactions that transforms the food you eat into the energy that keeps your heart beating, your muscles moving and your brain thinking.
B vitamins are woven throughout that process. They aren't energy, but they are the tools your body uses to make it.
As we get ready to embrace a new season, ensure you're getting enough!
References
- Kennedy DO. B Vitamins and the Brain: Mechanisms, Dose and Efficacy—A Review. Nutrients. 2016;8(2):68. doi:10.3390/nu8020068.
- Depeint F, Bruce WR, Shangari N, Mehta R, O'Brien PJ. Mitochondrial function and toxicity: role of the B vitamin family on mitochondrial energy metabolism. Chemico-Biological Interactions. 2006;163(1–2):94–112. doi:10.1016/j.cbi.2006.04.014.
- Tardy AL, Pouteau E, Marquez D, Yilmaz C, Scholey A. Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence. Nutrients. 2020;12(1):228. doi:10.3390/nu12010228.
- Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academies Press; 1998. doi:10.17226/6015.