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Strong evidenceVitamins

Vitamin B12

Also called: Methylcobalamin, cyanocobalamin, cobalamin

Needed for energy, nerves and red blood cells. Vegetarians and people on metformin or acid reducers often run low.

Typical amount
500–1,500 mcg a day for people low in B12 (RDA 2.5 mcg)
Best time
Morning · Timing guide
Food
With or without food
Typical course
12 weeks, then review
Upper limit
No set upper limit; high-dose injections are prescription only
Is it right for me?

Where to buy

3 products
Also inside 9 other products (combinations and multivitamins)

What is Vitamin B12?

Vitamin B12 is found almost only in animal foods, so vegetarian and vegan diets often fall short. The body uses it to make red blood cells, keep nerves healthy and turn food into energy. Low B12 can cause tiredness, brain fog, tingling in the hands and feet, and a sore tongue. Methylcobalamin is the most common supplement form in India.

Forms. Tablets, sublingual tablets, sprays and oral strips. Methylcobalamin and cyanocobalamin both work. Injections are for severe deficiency and are given by a doctor.

What it may help with

Evidence grade

Strong: several good human trials. Moderate: some trials, mixed results. Limited: small or early studies. Traditional: long use, little trial evidence.

Safety and interactions

Side effects
Very safe; extra B12 is passed out in urine. Rarely causes acne or mild stomach upset at high doses.
Who should be careful
Metformin and acid reducers lower B12; take folate only with B12 checked
Stop and call a doctor if
Rash, palpitations

Food sources

Milk, curd, paneer, eggs, fish, meat and B12-fortified foods.

Common questions

I'm vegetarian. Do I need B12?

Very likely. Most vegetarians don't get enough from dairy alone. A blood test can confirm.

How long until I feel a difference?

People who are low often notice more energy in 2–4 weeks; blood levels take about 3 months to settle.

Can I take it with metformin?

Yes. Metformin lowers B12 over time, so many doctors suggest a B12 supplement alongside it.

Sources

For information only, not medical advice. Prices and links are checked by hand and can change; we may earn a small commission on some links. This plan is based on your answers and is not a medical diagnosis. It does not replace advice from your doctor. If you take medicines or have a health condition, check with your doctor before starting any supplement.