Most adults under-consume B12, and the recovery format depends on how deficient the person is and how reliably they will take it. The three common delivery options — water, tablets, injections — are not interchangeable. Each fits a different scenario.
B12 water
Lowest friction. Lives in the bottle the person was already going to drink. Typical dose is 2.5 to 5 micrograms per 750ml, which covers a normal-range daily requirement in one bottle. Best for maintenance and mild deficiency. Not the right format for someone seriously deficient who needs a higher single dose to recover.
B12 tablets
Higher dose per delivery — typical OTC tablets sit at 500 to 1000 micrograms. The body absorbs only a small percentage at oral doses this high; the rest is excreted. Tablets work for recovering from mild-to-moderate deficiency and as a regular supplement when reliability of intake is a concern. Best taken with food.
B12 injections
Highest dose, fastest absorption — typical clinical injections deliver 1000 micrograms intramuscularly, bypassing the stomach entirely. Required for clinically diagnosed deficiency, especially in cases where oral absorption is the underlying problem (PPI users, pernicious anemia, post-bariatric surgery). Done in cycles under medical supervision, not for casual use.
Which is right for whom
- Vegetarian with no symptoms, normal blood work — B12 water as maintenance.
- Mild deficiency caught on a blood test — tablets daily for two to three months, then re-test.
- Moderate-to-severe deficiency or PPI user — start with injections under a doctor, follow up with tablets.
- Athletes, regular gym-goers, anyone managing fatigue — B12 water as a daily-driver addition.
B12 water is for prevention and maintenance. Tablets are for correction. Injections are for recovery. Use them for what they are for.