vitamin b12 dosage for adults

What is the Recommended Vitamin B12 Dosage for Seniors?

Last modified on October 23rd, 2023

The recommended vitamin B12 dosage for seniors is important to understand, because many older people are deficient in B12. The symptoms of B12 deficiency in seniors or people of any age can be harmful when left untreated. We explore what you should know about the proper B12 dosage for seniors and B12 in general.

Key Takeaways

  • Mayo Clinic’s experts, among other health officials, have recommended older adults take a B12 supplement.
  • B12 is essential for red blood cell formation, bone health, nerve function, and metabolism.
  • Anywhere from 5 to 15% of adults have a B12 deficiency. It’s more common the older you get.
  • Symptoms of B12 deficiency are similar to other common signs of aging, so it may be overlooked.
vitamin b12 dosage for seniiors

The Importance of Vitamin B12

Vitamin B12 is an essential nutrient. Your body can’t create it. You need B12 from your diet or a supplement.

One of the biggest roles of B12 is to produce red blood cells. B12 also makes DNA and supports the nervous system. Vitamin B12 helps with bone health and metabolism.

If you’re deficient in vitamin B12, it can lead to physical and psychological symptoms. Many of the problems stemming from B12 deficiency are linked to a lack of healthy blood cells. Your body requires healthy blood cells to transport oxygen throughout your body. You also need healthy blood cells to ensure the health of your organs.

B12 is a water-soluble vitamin. It’s found in foods like red meat, eggs, poultry, dairy, and fish.

Vitamin B12 Deficiency

For someone wondering what the recommended vitamin B12 dosage is for seniors, it may be because they’re already experiencing symptoms.

Symptoms of B12 deficiency in seniors or people of any age can include:

Tingling Feet and Hands

When you have a B12 deficiency, it can lead to the sensation of pins and needles in your hands and feet.

B12 is essential for the functioning of your nervous system.

If you have a deficiency, it can lead to nerve damage or cause problems with nerve conduction.

B12 helps your body product myelin. Myelin protects your nerves and helps them transmit feelings and sensations.

When you don’t have enough B12, you then can’t make enough myelin to cover your nerves. That leads to nerve damage.

Since the feeling of pins and needles is common in older people, it’s important to ask what the correct vitamin B12 dosage for seniors is.

Movement Problems

If you have peripheral nerve damage due to ongoing B12 deficiency, you may have problems with movement.

If you have numbness in your limbs and feet, you could need help or support walking. You might also have muscle weakness and reduced reflexes.

If you’re a senior and experience movement issues related to B12 deficiency, it can put you at greater risk of falling.

Pale Skin

Pale skin or skin that looks yellow may indicate a B12 deficiency.

Your body’s skin may look pale or jaundiced because you cannot produce enough red blood cells.

B12 deficiency is linked to something called megaloblastic anemia. This type of anemia means you have a lack of red blood cells. Megaloblastic anemia can also weaken your blood cells. Weak red blood cells break down more quickly.

When your body breaks down red blood cells, the liver releases bilirubin. Bilirubin is a substance that can cause jaundice.


Fatigue is one of the most common symptoms of B12 deficiency. When you don’t have enough red blood cells, oxygen can’t be transported, leading you to feel tired.

Rapid Heart Rate

Your heart could beat faster in an attempt to make up for the reduction in red blood cells.

Anemia pressures your heart to push out more blood and to do so faster.

Shortness of Breath

If you feel like you’re short of breath and particularly are also experiencing a fast heartbeat, it could be because of anemia linked to B12 deficiency.

Oral Pain

B12 plays a role in oral health.

Deficiency can cause ulcers or a burning sensation in the mouth. It can also cause something called glossitis, which is a smooth, red, swollen tongue.

The reason is that less oxygen reaches the tongue.

Cognitive Impairment

Memory and thinking problems can result from B12 deficiency.

One study found an association between an increased risk of Alzheimer’s disease, vascular dementia, and Parkinson’s because of low levels of B12.

Mood Disturbances

B12 is linked significantly to mental health.

If you’re deficient you may experience symptoms like depression and irritability.

It may be due to B12’s role in breaking down a chemical in the brain called homocysteine.

If you have too much homocysteine, it can cause mental health problems.

Who Is at Risk for B12 Deficiency?

Some groups of people are more likely to be B12 deficient than others.

First, you may have a gut or digestive health condition that impairs your body’s ability to absorb B12. These conditions include celiac disease, Crohn’s disease, atrophic gastritis, and pernicious anemia. If you have these conditions, it can be a good idea to take a liquid B12 supplement because they’re easier for the body to absorb.

Other factors that put you at greater risk of B12 deficiency are:

  • For older people—your body’s ability to absorb B12 diminishes as you age.
  • Being a vegan or vegetarian.
  • Taking anti-acid medicines for an extended period.
  • Weight loss or stomach surgery.
  • Taking Metformin for diabetes.
  • Excessive alcohol use.
  • Failure to produce adequate stomach acid either due to medicines or a weakening of the stomach lining.

If you’re experiencing any of the symptoms above or fall into a high-risk category for B12 deficiency, speak to your doctor. There are standard blood tests that can be used.

Having your doctor check your B12 levels should be a priority if you even suspect a deficiency. It may be difficult if not impossible to reverse deficiency if it’s left untreated.

The longer a B12 deficiency goes untreated, the more likely the symptoms can’t be reversed.

What is the Right Vitamin B12 Dosage for Seniors?

This all brings us back to our original question. What is the correct vitamin B12 dosage for seniors?

An estimated 20% of people 50 or older may have low vitamin B12 intake.

Adults should aim to get 2.4 micrograms of B12 daily. This includes older adults.

Even though that is the recommended dosage, there are a few other things to know as far as the right vitamin B12 dosage for seniors.

First, if you’re getting B12 from supplements, you don’t absorb the entire amount of the vitamin in each dose. Because of the risk of poor absorption, the National Academy of Medicine recommends that if you’re over 50, you get your vitamin B12 needs met through supplements and fortified foods.

There was an 8-week study of older adults, and it took 500 mcg of vitamin B12 to normalize levels in 90% of participants. For some older people, doses of up to 1000 mcg were needed.

For someone with severe B12 deficiency, they may need to get injections to correct levels.

There’s not really a risk of taking too much vitamin B12. It’s water-soluble, so your body will eliminate what you don’t need in your urine.

If you’re a senior, aim for a high-dose oral B12 supplement ranging from 1000 to 2000 mcg a day. Again, as touched on, this will compensate for your body’s challenges with absorption. This is well above the recommended amount, but you must consider absorption. A lack of absorption is one of the big reasons seniors are often B12 deficient.

Final Thoughts—Vitamin B12 Dosage for Seniors

Vitamin B12 deficiency is very common among seniors.

Untreated, it can lead to serious health effects. If you’re a senior, speak to your doctor about testing your B12 levels. If you’re using a supplement, the vitamin B12 dosage for seniors may need to be higher than for younger adults to make up for problems with absorption.

After speaking to your doctor, an effective vitamin B12 dosage for seniors, if you’re taking a supplement, could be anywhere from 1,000 to 2,000 mcg a day.

We encourage you to look at our post on the best vitamin B12 supplements, which are easy to take highly absorbable and bioavailable.

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