February 14th 2026
By Ari Parker
Learn the recommended vitamin B12 dosage for seniors over 65, signs of deficiency, and how to get enough B12 through diet, supplements, and injections.
By Ari Parker
Vitamin B12 is an important nutrient. It supports brain function, the nervous system, heart health, and bone health. Vitamin B12 comes from animal products like meat, fish, eggs, and dairy. You can also find it in some fortified foods, including cereals and plant-based milks. However, up to 30% of adults over 50 have difficulty absorbing vitamin B12 from food. The good news is that vitamin B12 levels can be easily managed with proper supplementation.
In this article, we’ll go over the recommended vitamin B12 dosage for seniors and what signs and symptoms of B12 deficiency to look for. We’ll also discuss which vitamin B12-rich foods you can add to your diet.
Up to 30% of adults over 50 have difficulty absorbing vitamin B12 from food, making supplementation often necessary.
While the recommended daily intake is 2.4 mcg for adults, many experts recommend 25-100 mcg B12 supplements for older adults due to absorption challenges.
B12 deficiency in seniors can lead to serious issues like fatigue, memory problems, and nerve damage. Fortunately, it’s easy to prevent and treat.
Vitamin B12 is considered an essential nutrient. It helps with nerve function, red blood cell formation, cognitive health, and bone health. It can also support mood and eye health. However, vitamin B12 deficiency is more common in the elderly. As people age, their stomach acid and digestive enzymes decrease, which can impact how B12 is absorbed.
When you eat food containing B12, B12 is “bound” to the food, and your body uses stomach acid to release it. Once in the small intestine, the body uses a carrier protein called intrinsic factor to absorb the B12. For seniors who have low stomach acid or intrinsic factor, this can mean that their bodies aren’t able to absorb enough vitamin B12 from the food they eat.
Seniors are also more likely to be taking medication that can interfere with the absorption of B12. These medications include metformin for diabetes and proton pump inhibitors (PPIs) or H2 blockers for acid reflux. Some medical conditions, including celiac disease and Crohn’s disease, can also impact the way the body absorbs B12.
The recommended daily intake of B12 is 2.4 mcg per day for adults. But many experts suggest seniors take 25-100 mcg of oral supplements to counter any absorption issues. Those with a vitamin B12 deficiency may be prescribed higher doses of up to 1,000 mcg, since only a small percentage of it is absorbed.
Because vitamin B12 is a water-soluble vitamin, the body excretes what it doesn’t need. However, it’s important to consult with your doctor before starting a new supplement. They can perform a blood test to check for vitamin B12 deficiency and monitor how well your supplement is working.
In general, B12 supplements for older adults are safe, accessible, and affordable. Because vitamin B12 supplements contain vitamin B12 that isn’t bound to food, it’s easier to absorb, even for people who have low stomach acid. Sublingual (under the tongue) supplements or lozenges offer a convenient option that is just as effective as oral supplements in people with absorption issues.
When picking a vitamin B12 supplement, choose one that is third-party tested. Look for certifications from USP, NSF, or ConsumerLab. This ensures the supplement has what it claims and is free from any contaminants like heavy metals.
The best way to take vitamin B12 is in the morning on an empty stomach. This helps your body absorb more vitamin B12 because it’s not competing with other nutrients from the food you eat.
Because vitamin B12 is water-soluble, it’s not stored in the body for long. This means that it’s important to take supplements regularly, once per day or as otherwise directed by your doctor.
Taking a vitamin B12 supplement with a full glass of water can help it dissolve and be easily absorbed. Pairing it with a B-vitamin complex can also increase its effectiveness. However, it’s best to avoid taking some supplements, such as vitamin C, at the same time as vitamin B12, as it can interfere with absorption.
For individuals who are very low on vitamin B12, their doctors might recommend a prescription nasal spray or injection. These can help to raise vitamin B12 levels more quickly than an over-the-counter supplement. In rare cases, taking very high doses of vitamin B12 can cause headaches, stomach issues, and weakness. If you’re experiencing these symptoms, contact a healthcare professional.
The signs and symptoms of B12 deficiency can be general and may overlap with other causes. Some symptoms may also be mistaken for normal aging. This is why it is important to ask your doctor to test you for vitamin B12 deficiency if you start developing symptoms. Common B12 deficiency symptoms in seniors include:
Fatigue or weakness
Pale skin
Shortness of breath and heart palpitations
Loss of appetite
Sore and red tongue; mouth ulcers
Numbness and tingling (“pins and needles”) in the hands or feet
Difficulty walking and problems with balance
Vision changes
Memory loss and confusion
Slower thinking
Depression and irritability
Diarrhea or constipation; nausea
Vitamin B12 is found naturally in animal-based sources and fortified foods. Meat, poultry, and fish all contain vitamin B12. Lean protein sources such as lean cuts of beef and pork, tuna, and salmon are rich in vitamin B12 and protein while being low in cholesterol-raising fats. The same is true for non-fat or low-fat dairy sources, including yogurt, milk, and kefir. Eggs are another good source of vitamin B12.
Because vitamin B12 occurs in animal-based foods, it can be harder for vegetarians and vegans to get enough vitamin B12 from the food they eat. Most vegetarians and vegans do need to take a vitamin B12 supplement. However, some foods are fortified with vitamin B12. These include fortified cereals, nutritional yeast, and plant-based milks.
Pairing foods that contain vitamin B12 with protein can help to increase its absorption. It’s also recommended to spread your B12 intake throughout the day, as the body can only absorb so much at once.
| Serving | Vitamin B12 content in micrograms |
|---|---|
| 3 ounces of salmon | 2.7 |
| 3 ounces of canned tuna fish | 2.5 |
| 2 tablespoons of nutritional yeast (check label) | 4-12 |
| 3 ounces of beef (85% lean meat/15% fat) | 2.4 |
| 6 ounces of nonfat Greek yogurt | 1 |
| 1 cup of low-fat dairy milk | 1.2 |
| 1 cup of almond milk (check label) | 0.8-1.2 |
| 3 ounces of ham | 0.6 |
| 1 cup of fortified breakfast cereal (check label) | 0.6 |
| 1 large egg | 0.6 |
| 3 ounces of chicken breast | 0.3 |
Vitamin B12 is essential for seniors, but deficiency can be common due to age-related absorption changes. However, B12 supplementation is safe, affordable, and effective at preventing and treating deficiencies. 25-100 mcg supplements are generally recommended for seniors, but individual needs can vary. Seniors showing B12 deficiency symptoms should see their doctors for testing. A high-quality B12 supplement for seniors can help prevent and manage deficiency effectively.
While the RDA is 2.4 mcg, most experts recommend 25-100 mcg supplements for seniors over 65 due to absorption challenges. However, some seniors, especially those with a B12 deficiency, may need higher doses.
Fatigue, memory problems, weakness, numbness or tingling in extremities, balance issues, mood changes, and pale skin are common B12 deficiency symptoms in seniors.
B12 has no established upper limit and is very safe. The body excretes any excess through urine, so there are minimal side effects, even at high doses.
Ashley, R. D., MD. (2018, August 15). Ask the Doctors – Are large doses of B12 safe? UCLA Health. https://www.uclahealth.org/news/article/ask-the-doctors-are-large-doses-of-b12-safe
Harvard Health Publishing. (2021, March 8). Should you take a vitamin B12 supplement? Harvard Health. https://www.health.harvard.edu/staying-healthy/should-you-take-a-vitamin-b12-supplement
Katella, K. (2024, June 26). Are you getting enough vitamin B12? What you need to know. Yale Medicine. https://www.yalemedicine.org/news/are-you-getting-enough-vitamin-b12
Mayo Clinic Staff. (2025, August 13). Vitamin B-12. Mayo Clinic. https://www.mayoclinic.org/drugs-supplements-vitamin-b12/art-20363663
Office of Dietary Supplements, National Institutes of Health. (n.d.). Vitamin B12 – Fact sheet for health professionals. U.S. Department of Health & Human Services. https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/
Park, S., & Johnson, M. A. (2006). What is an adequate dose of oral vitamin B₁₂ in older people with poor vitamin B₁₂ status? Nutrition Reviews, 64(8), 373–378. https://doi.org/10.1111/j.1753-4887.2006.tb00222.x
Stover P. J. (2010). Vitamin B12 and older adults. Current opinion in clinical nutrition and metabolic care, 13(1), 24–27. https://doi.org/10.1097/MCO.0b013e328333d157
