B vitamins: who should take which kind, and how much

What are B vitamins?

"B vitamins" is the name for eight vitamins grouped together: B1, B2, B3, B5, B6, B7 (biotin), B9 (folate) and B12. They're all water-soluble, so your body doesn't store them for long, and any extra leaves in your urine.

In a word, their job is to be the gears that turn the food you eat into energy. All eight mesh together in the same process. That's why the standard approach is a complex (B complex) with B1 through B12 in balance, rather than a lot of just one.

Vitamin B benefits: what each type does

Here are the effects people notice most:

• Fatigue: The most basic fatigue supplement, and one people tend to feel quickly.
• Muscle pain, nerve pain, numbness and tingling: Many people say tight shoulders and upper back, and tingling, eased when they took plenty of B12.
• Managing homocysteine: B6, folate and B12 work together to lower homocysteine, an amino acid byproduct that's harmful to blood vessels.
• Period cramps: Studies found that taking a high dose of about 100 mg of B1 consistently reduced period pain.

Who needs them

The more of these apply to you, the more worth trying they are:

• □ Getting up in the morning is really hard, and you often work late or overwork
• □ Your shoulders and neck are always tight, or you have numbness, tingling or nerve pain
• □ When you're tired, mouth sores or cracked mouth corners keep coming back
• □ You go to a lot of happy hours and work dinners
• □ Brain-heavy work and stress leave you mentally drained
• □ You take a multivitamin but are still tired

Some people are especially likely to run low on B12:

• People over 50: Less stomach acid means you don't absorb B12 from food as well.
• People who eat little meat or dairy, and vegetarians
• People who've taken birth control pills for years: The pill uses up B vitamins, which can lead to fatigue, low mood and sleep problems.

Who doesn't need a high dose, or should be careful

• Teens, and people just aiming for general health: You don't need a high dose. The B vitamins in a multivitamin are often enough.
• People with gout: High-dose B3 (niacin) can raise uric acid and make gout worse.
• People with serious kidney stone problems: Talk to your doctor before taking them.
• People with a sensitive stomach: Start with a lower dose.
• Older adults, children, and people who've had neuropathy: You may be sensitive to B6, so keep the dose low.

What are active B vitamins? Differences by form

Active forms are forms your body can use right away. They're 2–3 times more usable than regular forms and tend to be easier on the stomach, so they're widely recommended these days.

Cyanocobalamin, a form of B12, is the cheap, common regular form. If nerve pain is your goal, choose methylcobalamin.

When to take B vitamins and daily dose

Bottom line: 1 capsule with about 50 mg each of B1, B2 and B6, after breakfast or lunch.

1. Take them after meals. In theory they absorb better on an empty stomach, but high doses often cause heartburn and nausea. If your stomach is sensitive, take them during a meal.
2. Avoid the evening. They have an energizing effect that can interfere with sleep.
3. If you take 2 capsules, split them between breakfast and lunch. Extra amounts leave quickly in your urine, so splitting is more efficient.
4. Give it at least 1–2 weeks before judging. Once your fatigue eases, you can switch to a multivitamin for maintenance.

Vitamin B6 upper limit: always add it up

The B vitamin to be most careful with is B6. Taking a lot for a long time can cause peripheral neuropathy (damage to the nerves in your hands and feet that causes tingling and numbness).

• The US upper limit is 100 mg a day. South Korea's is stricter at 50 mg, and Europe's at about 12 mg.
• Problems mostly occur when people take the regular form (pyridoxine hydrochloride) at more than 100–200 mg for several months or longer. But in sensitive older adults and women, rare cases have been reported at around 50 mg.
• Most people recover after stopping.

B6 is also in multivitamins, magnesium products with B6, joint and eye supplements, and energy drinks. Add up all your labels and keep it at 100 mg a day or less, ideally under 50 mg.

Stop right away if you notice:

• Prickling, burning or tingling in your fingertips or toes
• Reduced feeling
• Dizziness, trouble with balance, or weakness in your legs

How to choose B vitamins: 4 things to check on the label

1. Does it contain all 7: B1, B2, B3, B5, B6, folate and B12? — Some products leave out B1, B2 or B5.
2. Amount per capsule — 20–50 mg or more each of B1, B2 and B6 is a solid choice. At 1–2 mg, you're unlikely to feel less tired.
3. Forms of B1 and B12 — Benfotiamine and methyl- or adenosylcobalamin are good signs. For folate, check for 5-MTHF.
4. B6 amount — Make sure it doesn't push you over 100 mg when combined with your other supplements.

Think twice about these products:

• Gummies: Water-soluble vitamins break down easily, so potency is hard to guarantee, and many ingredients are missing.
• Very cheap products: They often smell strongly and discolor easily.

Vitamin B side effects: what to do if your stomach is upset

The most common issue is stomach upset. Nausea, pain just below the breastbone, and a vitamin taste coming back up are typical, and they're more likely at higher doses.

1. Take them during or right after a meal
2. Split your daily amount
3. Switch to a lower-dose product
4. If it still continues, switch to another brand

• Insomnia: If you took them in the evening, move them to the morning.
• Flushing and itching: Sudden facial warmth and redness (flushing) mainly comes from the niacin form of B3. The niacinamide form rarely causes it.
• High-dose niacin (1,000 mg or more a day): Can raise liver enzymes. If you're taking it for cholesterol, don't do it on your own — do it with liver tests from your doctor.
• High-dose biotin: Can throw off thyroid and heart-related blood test results. Skip it the day before a test.

Supplements that pair well with B vitamins

The most common fatigue combo is B vitamins + magnesium. For muscle tightness and tingling, B12 with magnesium tends to work well. If you need more energy, add CoQ10 (B vitamins handle the early steps in your cells' energy factory, and CoQ10 handles the last step) or arginine; if stress has worn you out, add rhodiola, ashwagandha or theanine.

Brewer's yeast overlaps in ingredients and can upset your stomach, so take it at a different time.

Combinations

Works well with: Magnesium, Coenzyme Q10 (CoQ10), L-Arginine, Rhodiola, Ashwagandha, L-Theanine, Vitamin C, Milk thistle, Alpha-Lipoic Acid, Carnitine

Space apart from: Brewer's Yeast

Frequently asked questions

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