VITAMIN B12: WHY YOU NEED IT

Adapted from resources by the National Institute on Aging (NIA) and NIH Office of Dietary Supplements (ODS)

You might be eating the right foods and still coming up short.

That's the quiet reality with vitamin B12 — one of the most commonly under consumed nutrients among older adults. The issue usually isn't what's on your plate. It's whether your body can still absorb what you're eating.

Why absorption becomes the challenge

As we age, the stomach lining naturally changes. For some people, those changes reduce the production of stomach acid needed to release B12 from food proteins — a condition called atrophic gastritis. According to the National Institute on Aging, it affects an estimated 8 to 9 percent of adults 65 and older. Certain commonly prescribed medications can compound the problem: proton pump inhibitors, widely used for acid reflux, have a similar acid-reducing effect.

Why it often goes unnoticed

B12 deficiency is easy to miss because the body stores reserves in the liver — reserves that can take years to deplete. By the time symptoms appear, they can look a lot like things people attribute to aging: fatigue, memory changes, or numbness in the hands and feet. That overlap is what makes early attention to B12 status so worthwhile.

What to eat — and what form matters

The recommended daily intake of B12 for adults is 2.4 micrograms. Natural sources include meat, fish, poultry, eggs, and dairy. But for older adults with reduced stomach acid, the form found in fortified foods and supplements — called crystalline B12 — may actually be absorbed more reliably than the B12 bound to protein in whole foods, because it doesn't depend on stomach acid to be released.

Practical sources of crystalline B12 include fortified breakfast cereals and nutritional yeast, both of which are accessible, affordable, and easy to incorporate into a regular routine.

When to ask your doctor

If you take medication for acid reflux, or if fatigue or cognitive changes have become a concern, it's worth asking your health care provider whether checking your B12 status makes sense. A simple blood test can identify a deficiency — and addressing one early is far easier than treating the consequences of one that went undetected for years.

For more information, visit ods.od.nih.gov.