A B complex bundles several B vitamins into one supplement. Here's what each one does, what the research supports, and who is most likely to benefit.
Written by Vita Globe Editorial Team | Reviewed against NIH Office of Dietary Supplements guidance and peer-reviewed research | Updated October 7, 2026
Quick Answer
A vitamin B complex is a supplement that combines several B vitamins. B vitamins act as helpers (coenzymes) that let your body turn food into usable energy, make red blood cells, and keep nerves working normally[1][2]. A B complex does not add energy on its own. It helps most when your diet, age, or a medication leaves you short on one or more B vitamins[3].
In this article
What is a vitamin B complex?
There are eight B vitamins: thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), B6, biotin (B7), folate (B9) and B12. They are water-soluble, so your body doesn't store most of them in large amounts and you need a steady supply from food[1]. A "B complex" is any supplement that combines several of them. Formulas vary, so the label tells you which B vitamins are included and how much.
What does each B vitamin do?
- Niacin (B3): becomes NAD and NADP, which take part in hundreds of reactions that release energy from food[4].
- Pantothenic acid (B5): is used to make coenzyme A, which the body needs to build and break down fats[5].
- Vitamin B6: helps more than 100 enzymes, mostly in protein metabolism, and is involved in making neurotransmitters[6].
- Biotin (B7): helps enzymes that process fats, carbohydrates and protein[7].
- Folate (B9): is needed to make DNA and for normal cell division, which is why it matters so much before and during pregnancy[8].
- Vitamin B12: is needed for red blood cell formation, nerve function and DNA synthesis[3].
Why are B vitamins grouped together?
B vitamins work in overlapping pathways. Folate and B12 work together to make DNA, and B6, B12 and folate all help process homocysteine[2]. Shortfalls also tend to show up together, for example in people who drink heavily or have trouble absorbing nutrients[8]. Covering several B vitamins at once is practical when you don't know which one you might be low in.
Who benefits most from a B complex?
- Vegans and vegetarians: B12 comes almost only from animal foods[3].
- Older adults: B12 deficiency rates in community-dwelling older adults range from about 3% to 43% depending on the study[3].
- People taking metformin or acid reducers: both can lower B12 absorption[3].
- People with low-variety diets or digestive conditions such as celiac or Crohn's disease[6][8].
What can't a B complex do?
If your B vitamin levels are already adequate, research does not show that taking more boosts energy or performance[2]. A B complex also can't fix tiredness caused by poor sleep, low iron, thyroid problems or stress. If you're tired all the time, see a doctor rather than relying on a supplement.
Our option
Vita Globe Vitamin B Complex Gummies
One strawberry gummy a day provides six B vitamins: B12 20mcg, niacin 12mg, B6 1.2mg, folate 430mcg DFE, biotin 50mcg and pantothenic acid 6mg, plus vitamin C 10mg and inositol 3.5mg. Vegan, non-GMO and gluten-free, 60 gummies per bottle.
Frequently asked questions
Is a B complex the same as a multivitamin?
No. A B complex only covers B vitamins (sometimes with vitamin C). A multivitamin covers a wider range of vitamins. See B Complex vs. a Multivitamin.
Does a B complex give you energy?
B vitamins help your body release energy from food, but extra B vitamins don't add energy if you're not low[2]. More in B Vitamins and Energy.
Is it safe to take a B complex every day?
For most adults, yes, at label doses. Niacin, B6 and folic acid have upper limits, so add up all your supplements. See B Complex Side Effects and Upper Limits.
Why does B complex make urine bright yellow?
That color comes from riboflavin (B2), which the body passes in urine. Formulas without riboflavin, like ours, are less likely to cause it.
Sources
- NIH Office of Dietary Supplements. Dietary Supplements: What You Need to Know. ods.od.nih.gov
- Kennedy DO. B Vitamins and the Brain: Mechanisms, Dose and Efficacy — A Review. Nutrients. 2016;8(2):68. doi:10.3390/nu8020068
- NIH ODS. Vitamin B12 Fact Sheet for Health Professionals. ods.od.nih.gov
- NIH ODS. Niacin Fact Sheet for Health Professionals. ods.od.nih.gov
- NIH ODS. Pantothenic Acid Fact Sheet for Health Professionals. ods.od.nih.gov
- NIH ODS. Vitamin B6 Fact Sheet for Health Professionals. ods.od.nih.gov
- NIH ODS. Biotin Fact Sheet for Health Professionals. ods.od.nih.gov
- NIH ODS. Folate Fact Sheet for Health Professionals. ods.od.nih.gov
About the Vita Globe Editorial Team
The Vita Globe Editorial Team researches and writes our wellness content from peer-reviewed research and guidance from bodies such as the NIH and FDA. We cite sources inline and update articles when the evidence changes.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and is not a substitute for medical advice. Talk to your healthcare provider before starting any new supplement, particularly if you are pregnant, nursing, taking medication, or managing a health condition.
