The B12 Guide

Why this is the one supplement that matters

B12 is made by bacteria, not by plants or animals. Animals get it because the bacteria live in their gut, in their feed, or because they're injected with it (most cattle in industrial systems are supplemented — meaning your steak's B12 came from a supplement before yours did).

You can't reliably get B12 from plant food. Spirulina and fermented foods are sometimes claimed as sources — they're not bioavailable. Supplement and stop worrying.

How much, what form, how often

Infographicdosing-matched.png — B12 dosing at a glance: 500–1000 mcg 2–3× a week, 2000 mcg once a week, or 50 mcg dailyb12

• Form: methylcobalamin. (Cyanocobalamin also fine, slightly cheaper.)
• Dose: 500–1000 mcg, 2–3 times a week. Or 2000 mcg once a week. Or 50 mcg daily.
• How to take: chewable or sublingual is absorbed better than swallowed.

The body only absorbs a small fraction per dose, which is why high single doses work — anything extra is excreted harmlessly.

Brands in India

• HealthKart B12
• Carbamide Forte B12
• Wellbeing Nutrition Methylcobalamin
• Inlife Methylcobalamin
• Nature Made (imported, on Amazon)

₹300–₹600 for several months. Cheaper than chai.

How to test

Ask your doctor for:

• Serum B12 (>300 pg/mL ideal, anything under 200 is deficient)
• Homocysteine (more accurate marker of functional B12 status)
• MMA (methylmalonic acid) if you want to be thorough — most accurate but expensive

Once a year is fine if you supplement consistently. Every 2 years if you've been stable.

Symptoms of deficiency

You don't want to wait for symptoms — by the time they show, deficiency is advanced. But for reference: fatigue, tingling in hands/feet, brain fog, low mood, pale skin, glossitis (smooth, sore tongue).

Common myths