Vitamin B12 explained: what it is and food sources
The NIH says vitamin B12 dissolves in water and helps make DNA, the genetic material in your cells. It occurs naturally in animal foods, and adults who are not pregnant or breastfeeding need 2.4 mcg a day. One of the products we reviewed lists vitamin B12, and its label prints 24 mcg per serving.
- What it is
- Vitamin
- What adults need a day (ages 19 and older)
- 2.4 mcg
- In the products we reviewed
- 1, its label prints the amount
What vitamin B12 is
- Vitamin B12 comes naturally from animal foods and is added to some plant foods, including breakfast cereals and nutritional yeasts.1
- Vitamin B12 dissolves in water and is available from foods, supplements, and prescription medicines.1
- Vitamin B12 helps keep blood and nerve cells healthy and helps make DNA, the genetic material in your cells.2
- Vitamin B12 occurs naturally in animal foods, while plant foods contain it only when it has been added.2
- Supplement forms include cyanocobalamin, adenosylcobalamin, methylcobalamin, and hydroxycobalamin.2
- Vitamin B12 supplements come in multivitamin and mineral products, B-complex products, and products containing only B12.2
- Some Vitamin B12 supplements dissolve under your tongue.2
Foods that have it2
- Fish
- Meat
- Poultry
- Eggs
- Milk
- Other dairy products
- Clams
- Oysters
- Beef liver
- Fortified breakfast cereals
- Fortified nutritional yeasts
How much vitamin B12 each product gives
Adults need 2.4 mcg a day
Before you take it
If you take medicines
- Omeprazole (Prilosec), lansoprazole (Prevacid), cimetidine (Tagamet), and ranitidine (Zantac)
- These stomach acid medicines can interfere with Vitamin B12 absorption from food by slowing stomach acid release.2
- Metformin
- Metformin might interfere with Vitamin B12 absorption and leave less Vitamin B12 in your blood.2
Ask a doctor first
- People over 50 should get most of their Vitamin B12 from fortified foods or supplements because their bodies can usually absorb it from these sources.2
- Vegetarians, vegans, and others who eat little or no animal food might not get enough Vitamin B12 from their diets.2
- Ask your healthcare provider for breastfeeding advice suited to your situation.3
These statements have not been evaluated by the FDA. A supplement is not a medicine.
The product we reviewed that lists vitamin B12
| Product | Form and serving | Vitamin B12 per serving | Our score | Price a bottle | Buy |
|---|---|---|---|---|---|
 SeroBurn#3 in weight loss support | Capsules2 capsules | 24 mcg1,000% of daily need | 9.3 | $49 | Check price |
Questions people ask
Is vitamin B12 water soluble?
Yes, vitamin B12 dissolves in water. The NIH says it helps make DNA, the genetic material in your cells.
What foods have vitamin B12?
Fish, meat, poultry, eggs, milk, and other dairy products naturally contain vitamin B12. Clams, oysters, and beef liver also contain it. Plant foods contain vitamin B12 only when it has been added, as in some fortified breakfast cereals and nutritional yeasts.
How much vitamin B12 do adults need per day?
Adults ages 19 and older need 2.4 mcg of vitamin B12 a day. The daily amount is 2.6 mcg during pregnancy and 2.8 mcg while breastfeeding. Ask a clinician before starting a supplement during pregnancy or breastfeeding.
Do vitamin B12 supplements contain 1,000 mcg?
Yes, the NIH says B12-only supplements typically contain 500 to 1,000 mcg of vitamin B12. B-complex supplements generally contain 50 to 500 mcg.
Can a vitamin B12 supplement dissolve under your tongue?
Yes, some vitamin B12 supplements dissolve under your tongue. Vitamin B12 is also available in multivitamin and mineral products, B-complex products, and products containing only B12.
Which products we reviewed contain vitamin B12?
SeroBurn lists vitamin B12 and is one of the products we reviewed. Its label prints 24 mcg per serving of 2 capsules.
Sources
The products, amounts and prices come from each product's label and checkout, as its review shows them. AI drafts our pages from listed sources, figures are checked against them, and we have not tried the products.
- 1NIH Office of Dietary Supplements, Vitamin B12 - Health Professionalods.od.nih.gov/factsheetschecked
- 2NIH Office of Dietary Supplements, Vitamin B12 - Consumerods.od.nih.gov/factsheetschecked
- 3NIH LactMed, Vitamin B12ncbi.nlm.nih.gov/bookschecked