B vitamins are such an important part of keeping your body functioning at its best. These essential vitamins (of which there are eight) help turn the food you eat into energy, support your brain health, and even contribute to glowing skin and healthy hair. They’re also essential for producing red blood cells, which keep you feeling strong and energized.
Let’s take a closer look at what each B vitamin does, how much you need, and the best ways to get them through your diet or supplements (such as a B complex or prenatal vitamin) if needed.
In this article:
What Do B Vitamins Do for Your Body?
There are eight B vitamins1 in total:
- Vitamin B1 (Thiamine)
- Vitamin B2 (Riboflavin)
- Vitamin B3 (Niacin)
- Vitamin B5 (Pantothenic Acid)
- Vitamin B6 (Pyridoxine)
- Vitamin B7 (Biotin)
- Vitamin B9 (Folate/Folic Acid)
- Vitamin B12 (Cobalamin)
B vitamins act as coenzymes in many metabolic processes2 that take place in the body every day. More specifically, B vitamins help:
- Convert carbohydrates, fats, and proteins into usable energy3
- Support the nervous system4
- Promote healthy skin, hair, and nails, including reducing acne
- Aid in red blood cell production
- Support brain function, cognitive health5, and mood regulation6
- Help with the production of neurotransmitters and balancing hormones
Wondering why B vitamins are grouped together? It's because they share similar roles in energy metabolism7 and other biochemical processes. Despite their similarities, each B vitamin has distinct functions, sources, and deficiency symptoms. In other words, each one is unique yet complementary.
Signs of Low B Vitamins
What are the symptoms of low B vitamins? Deficiency in any one or combination of B vitamins can lead to a number of mental and physical symptoms, depending on which vitamin is lacking and how severe the deficiency is. Common signs include:
- Fatigue and weakness: Often associated with low B12 or folate.
- Nerve issues: Tingling or numbness in hands and feet, linked to B12 or B6 deficiency.
- Skin problems: Cracks at the corners of the mouth or a swollen tongue may indicate B2 or B3 deficiency.
- Mood changes: Depression, irritability, or confusion can sometimes result from low levels of B6, B12, or folate.
- Anemia: A lack of B12 or folate can lead to megaloblastic anemia.
- Hair loss and/or brittle nails: These are sometimes linked to insufficient biotin.
Different B Vitamins: Roles, Food Sources, and Daily Needs
Vitamin B1 (Thiamine)
What does thiamine do, and how much thiamine per day do you need? Here's a rundown:
- Role: Converts carbohydrates into energy and supports nerve function.
- Sources: Whole grains like brown rice, oats, whole wheat bread, lentils, black beans, peas, pork, and sunflower seeds.
- Daily Needs: 1.2 mg for men8, 1.1 mg for women.
Vitamin B2 (Riboflavin)
What does riboflavin do, and what foods are high in riboflavin?
- Role: Aids in energy production and supports skin and eye health.
- Sources: Dairy products, eggs, green leafy vegetables, mushrooms, beef, lamb, and almonds.
- Daily Needs: 1.3 mg for men, 1.1 mg for women9.
Vitamin B3 (Niacin)
Is niacin vitamin B3? Yes, the two are the same. What foods have niacin? You'll find the most niacin in foods like beef, nuts, chicken, and turkey.
- Role: Supports energy production, DNA repair, and healthy skin.
- Sources: Meat, fish, poultry, peanuts, and fortified grains.
- Daily Needs: 16 mg for men10, 14 to 18 mg for women.
Vitamin B5 (Pantothenic Acid)
- Role: Helps synthesize coenzyme A, which is essential for fatty acid metabolism.
- Sources: Chicken, beef, potatoes, eggs, mushrooms, seeds, and avocados.
- Daily Needs: 5 mg for adults11.
Vitamin B6 (Pyridoxine)
What does vitamin B6 do? Does vitamin B6 help with nausea? Yes, for adults experiencing nausea, such as pregnant women, a high intake of vitamin B6 can sometimes help curb nausea.
- Role: Supports neurotransmitter synthesis, red blood cell production, hormone production, and immune health.
- Sources: Bananas, chicken, fish like salmon, chickpeas, potatoes, and fortified grains.
- Daily Needs: 1.3-1.7 mg for adults12.
Vitamin B7 (Biotin)
Does biotin help hair growth? Some research suggests that it does, especially when paired with adequate protein intake and a balanced diet (although it's not a magic bullet for thick hair). What foods have biotin? It's found in foods like egg yolks, organ meats like liver, beef, almonds, and walnuts.
- Role: Essential for fat and carbohydrate metabolism and hair and nail health.
- Sources: Eggs, nuts, seeds, liver and organ meats, yeast, and sweet potatoes.
- Daily Needs: 30 mcg for adults13.
Vitamin B9 (Folate/Folic Acid)
- Role: Crucial for DNA synthesis, cell division, and fetal development during pregnancy.
- Sources: Leafy greens, citrus fruits, beans, and fortified grains.
- Daily Needs: 400 mcg for adults14, 600 mcg during pregnancy.
Vitamin B12 (Cobalamin)
Will vitamin B12 keep you awake? Not necessarily, assuming you don't take very high amounts. This vitamin is needed for energy and mental performance, but it's not stimulating when taken in moderate dosages. What food has vitamin B12? You'll find it in many foods with protein, like meat and dairy, for example.
- Role: Essential for nerve health, red blood cell formation, and DNA synthesis.
- Sources: Meat, fish, eggs, dairy, nutritional yeast, and fortified plant-based products.
- Daily Needs: 2.4 mcg for adults15.
What to Look for in a Vitamin B Complex
While many people who eat a balanced diet may be able to get sufficient B vitamins from foods, supplements can be helpful for certain groups of people who eat a limited variety of foods or have higher needs for B vitamins. This can include pregnant women, vegetarians, and older adults who might struggle to eat or digest enough of certain vitamins.
Which B vitamins are in a B complex? Many B complex supplements contain all eight B vitamins, sometimes along with choline for additional support. Typically, these supplements provide 100% of the daily value for each B vitamin, but formulations can vary.
Here are some general guidelines for vitamin B complex supplementation:
- Vitamin B Complex dosage for adults:
Ideally, look for a B complex that includes the dosages below. Keep in mind that some people, like pregnant or breastfeeding women, older adults, or those with absorption issues, might need more, which should be guided by a healthcare provider.
- Vitamin B1 (Thiamin): 1.1 mg/day for women, 1.2 mg/day for men
- Vitamin B2 (Riboflavin): 1.1 mg/day for women, 1.3 mg/day for men
- Vitamin B3 (Niacin): 14 mg/day for women, 16 mg/day for men
- Vitamin B5 (Pantothenic Acid): 5 mg/day for adults
- Vitamin B6 (Pyridoxine): 1.3–1.7 mg/day (depending on age and sex)
- Vitamin B7 (Biotin): 30 mcg/day for adults
- Vitamin B9 (Folate/Folic Acid): 400 mcg/day for adults
- Vitamin B12 (Cobalamin): 2.4 mcg/day for adults
If you're looking for a quality B complex vitamin, consider my B Active Plus formula, which contains methylated B vitamins.
This formula features a combination of most B vitamins in their coenzyme forms, so the body does not have to phosphorylate them to use them in biochemical reactions. This formula also includes a proprietary blend of naturally occurring folates, trimethylglycine, and choline to further support methylation and absorption.
- Is it better to take B12 or a B complex vitamin? If you’re deficient in multiple B vitamins, a vitamin B complex vitamin is ideal. For specific deficiencies, like B12, individual supplementation is the best option, although a B complex won't hurt and can likely also be helpful.
- When to take B complex vitamins: Morning is best, as they can provide energy throughout the day.
- How much B vitamins is too much?: Excess intake of some B vitamins, like B6 and niacin, can cause side effects such as nerve damage or flushing. Stick to recommended dosages unless you're working with a healthcare provider who recommends a different amount.
Potential B Vitamins Side Effects
While B vitamins are generally safe, taking excessive amounts of certain B vitamins can potentially cause side effects. The good news is that because B vitamins are water-soluble16, excess amounts are usually excreted in urine, but high doses can still cause issues, including:
- Upset stomach
- Diarrhea
- Nausea
Here are specific side effects that can be caused by a very high intake of different B vitamins:
- Vitamin B3 (niacin): High doses may cause skin flushing, itching, nausea, and, in rare cases, liver damage.
- Vitamin B6 (pyridoxine): Chronic high doses can lead to nerve damage, resulting in numbness and tingling in the hands and feet.
- Vitamin B9 (folate): Over-supplementation may mask a vitamin B12 deficiency, potentially leading to nerve damage.
- Vitamin B12 (cobalamin): Rarely causes side effects, but extremely high doses may result in acne or other skin issues.
If you experience persistent or severe side effects, consult a healthcare provider. Always follow dosage recommendations to minimize risks.
Other FAQs About B Vitamins
1. Which foods have B vitamins?
Foods rich in B vitamins include eggs, dairy, meat, fish, poultry, leafy greens, legumes, nuts, seeds, and fortified cereals. Each B vitamin is found in varying amounts, so a diverse diet ensures adequate intake. See the images earlier in the article for foods you can eat to get your B vitamins.
2. Are B vitamins water-soluble?
Yes, B vitamins are water-soluble, meaning they dissolve in water and are not stored in the body. Because of this, they need to be consumed regularly through diet or supplements.
3. What are methylated B vitamins?
Methylated B vitamins are the bioactive forms of B vitamins, such as methylfolate or methylcobalamin. In most cases, the body can use these forms more easily and directly. They are especially beneficial for people with genetic variations that affect B vitamin metabolism.
4. Do B vitamins give you energy?
B vitamins are essential for converting food into energy by supporting metabolic processes, but they do not provide energy directly like calories do. Adequate B vitamin levels are vital for maintaining healthy energy production and metabolism.
5. Can B vitamins help with weight loss?
B vitamins play a role in metabolism by helping the body process fats, proteins, and carbohydrates. However, they are not weight-loss supplements and will not directly cause weight loss without a proper diet and exercise plan.
6. Can biotin cause weight gain?
No, there is no evidence that biotin causes weight gain. Biotin is, however, involved in supporting healthy hair, skin, and nails, as well as energy metabolism.
7. Is folate the same as folic acid?
Folate is the natural form of vitamin B917 found in foods like leafy greens, legumes, and avocados. Folic acid, on the other hand, is the synthetic form used in supplements and fortified foods. The body needs to convert folic acid into its active form (methylfolate), but this process may be less efficient for some individuals due to genetic factors.
8. Is choline a B vitamin? How much choline does someone need (including during pregnancy)?
Choline is not a B vitamin but is often grouped with them due to its role in metabolism. It's an essential nutrient, critical for brain development, liver function, and during pregnancy for fetal brain and nervous system development.
Adults need 425–550 mg/day, with higher needs during pregnancy and lactation. Choline-rich foods include egg yolks, beef liver, soybeans, and broccoli, but supplementation may be necessary, especially during pregnancy.
Key Takeaways on B Vitamins
- B vitamins help convert food into energy, supporting metabolism and maintaining healthy energy levels.
- They play key roles in brain function, memory, and maintaining a healthy nervous system.
- B vitamins like B6, B9 (folate), and B12 are also needed to produce red blood cells and prevent anemia.
- Biotin (B7) and other B vitamins can contribute to the health and growth of skin, hair, and nails.
- Since B vitamins are not stored in the body, they need to be replenished daily through foods (like meat, eggs, dairy, nuts, seeds, and grains) or supplements, such as a B complex supplement.
References
- https://pubmed.ncbi.nlm.nih.gov/35933667/ ↩︎
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4772032/ ↩︎
- https://nutritionsource.hsph.harvard.edu/vitamins/vitamin-b/ ↩︎
- https://medlineplus.gov/ency/article/002399.htm ↩︎
- https://pubmed.ncbi.nlm.nih.gov/34432056/ ↩︎
- https://pubmed.ncbi.nlm.nih.gov/31527485/ ↩︎
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9662251/ ↩︎
- https://ods.od.nih.gov/factsheets/Thiamin-HealthProfessional/ ↩︎
- https://ods.od.nih.gov/factsheets/Riboflavin-Consumer/ ↩︎
- https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/ ↩︎
- https://ods.od.nih.gov/factsheets/PantothenicAcid-Consumer/ ↩︎
- https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/ ↩︎
- https://ods.od.nih.gov/factsheets/Biotin-Consumer/ ↩︎
- https://ods.od.nih.gov/factsheets/Folate-Consumer/ ↩︎
- https://ods.od.nih.gov/factsheets/VitaminB12-Consumer/ ↩︎
- https://www.ncbi.nlm.nih.gov/books/NBK548710/ ↩︎
- https://ods.od.nih.gov/factsheets/Folate-Consumer/ ↩︎
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