6 "Supplemental" reasons the importance of vitamin B12 shouldn't be underestimated
- 4 Minute Read
Dietitians stress the importance of vitamin B12 because deficiency symptoms may become permanent. Do you get enough from your diet or absorb it properly? Learn the best vitamin B12 sources and whether you need a supplement.
Key Takeaways
- Vitamin B12 keeps your body running behind the scenes. It's essential for healthy nerves, red blood cells, and DNA.
- Getting enough B12 is only half the story. Your body also needs enough stomach acid and "intrinsic factor" to absorb it from food.
- Animal foods are the only natural source of B12. Fortified cereals, plant milks, and nutritional yeast can also help you meet your needs.
- Some people need to pay closer attention to their B12 levels. Older adults, vegans, people taking metformin or heartburn medications, and those with digestive conditions or weight-loss surgery have a higher risk of deficiency.
- If you're at risk, don't guess. Track your B12 intake with MyNetDiary. A blood test can check your B12 level, and your healthcare provider can recommend supplements if needed.
What is the importance of vitamin B12 to our bodies?
Although vitamin B12 (cobalamin) will not give you a sudden energy boost as some supplement labels imply, we rely on it for nerve function and making red blood cells and DNA.
Symptoms of B12 deficiency include tingling and numbness in the hands and feet, poor balance, memory issues, and difficulty concentrating. While many of these symptoms improve with treatment, the nerve damage can be permanent.
How is vitamin B12 absorbed?
It takes a two-step process to absorb vitamin B12 from food.
- Separating from protein - In food sources, vitamin B12 is attached to protein and cannot be absorbed this way. Our stomach acid helps separate B12 from the protein.
- Binding with "intrinsic factor" - In the small intestine, vitamin B12 must bind with intrinsic factor, a protein made in the stomach that allows B12 to get absorbed into the bloodstream.
When stomach acid levels are low or the stomach does not produce intrinsic factor, vitamin B12 absorption decreases, increasing the risk of deficiency.
Fortified foods and dietary supplements contain the free form of B12 (unbound to protein), so stomach acid is unimportant for digestion and absorption. Very high doses of supplements can overcome a lack of intrinsic factor.
What are sources of vitamin B12?
Food sources
Dietary sources of B12 include animal foods (fish/seafood, meat, poultry, eggs, milk, and cheese) and fortified foods (fortified breakfast cereal, soy milk, etc.).
For healthy adults, the RDA is 2.4 mcg per day. You can meet the RDA with several daily servings of animal or fortified plant foods.
| Food | Portion | B12 (mcg) |
|---|---|---|
| Cheerios | 1 cup | 2.0 |
| Cheese, Swiss | 1 ounce (28g) | 0.9 |
| Chicken breast | 3 ounces (85g), cooked | 0.2 |
| Cottage cheese, 2% | ½ cup | 0.5 |
| Egg | 1 large | 0.6 |
| Hamburger | 3 ounces (85g), cooked | 2.3 |
| Liver, beef | 3 ounces (85g), cooked | 60.0 |
| Milk, 2% | 1 cup (240ml) | 1.1 |
| Nutritional yeast, fortified | 1 tablespoon | 33.8 |
| Salmon, pink | 3 ounces (85g), cooked | 4.0 |
| Soy milk | 1 cup (240ml) | 3.0 |
| Tuna, canned light | ½ cup | 2.0 |
When you might need a vitamin B12 supplement
1. Over age 50
The Institute of Medicine (IOM) estimates that 10-30% of people over 50 may be unable to absorb naturally-occurring vitamin B12 due to lower stomach acid production. Therefore, the IOM recommends that people within this age group seek vitamin B12 from fortified foods or supplements.
2. Follow a vegan diet
Because only animal-based foods contain vitamin B12, vegans must take supplements or regularly eat B12-fortified foods.
3. Take heartburn medication
Proton pump inhibitors are acid reflux medications (e.g., Nexium, Prevacid, Prilosec, and Protonix) that reduce acid levels in the stomach, making it harder to absorb vitamin B12. Over time, these medications can increase the risk of B12 deficiency.
4. Take metformin (Glucophage)
People who take this common medication for diabetes or diabetes prevention are at higher risk of vitamin B12 deficiency, likely due to interference with absorption. The American Diabetes Association recommends that people taking metformin have their B12 levels monitored regularly.
5. Had weight-loss surgery
Gastric bypass and gastric sleeve surgeries reduce stomach size, leading to less acid and intrinsic factor production, both of which are required for B12 absorption. If you have undergone weight-loss surgery, it is critical to take recommended dietary supplements and have your blood vitamin levels monitored regularly.
6. Have a digestive disorder
Many digestive conditions increase the risk of B12 deficiency, including Crohn's disease, celiac disease, small intestinal bacterial overgrowth, and pancreatic insufficiency.
Taking vitamin B12 supplements
If you are at risk of B12 deficiency, ask your doctor about getting your blood levels tested. If you are deficient, your doctor may advise oral or injected supplements. Some people take sublingual (under-the-tongue) or nasal B12 supplements.
Frequently Asked Questions
Can I get enough vitamin B12 from food alone?
Most people can. However, if you follow a vegan diet or have trouble absorbing B12, fortified foods or supplements may be necessary.
Who is most likely to need a vitamin B12 supplement?
Supplements are often recommended for people over 50, those following a vegan diet, people taking metformin or long-term acid-reducing medications, individuals who've had bariatric surgery, and those with digestive disorders that affect absorption.
What are the symptoms of vitamin B12 deficiency?
Vitamin B12 deficiency often develops gradually. Common symptoms include fatigue, tingling or numbness in your hands or feet, poor balance, and memory or concentration problems. If you notice these symptoms, talk with your healthcare provider.
Can vitamin B12 give me more energy?
Not if your B12 levels are already normal. However, if you're deficient, treating the deficiency can improve fatigue and other symptoms.
If I’m low on B12, do I need a shot?
Not necessarily. Many people can raise their vitamin B12 levels with oral supplements. If your deficiency is severe or your body is unable to absorb B12, your healthcare provider may recommend injections instead.
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Nutrients->Other Vitamins & Minerals Nutrients->B12
Aug 5, 2026
