The U.S. Centers for Disease Control and Prevention (CDC) report that 39 percent of adults ages 60 and older take multi-vitamin pills, spending more than $8 billion on them each year. Highly respected researchers at Harvard and Columbia medical schools conducted a study of more than 3,500 people, ages 60 and older, and found that compared to those who took a placebo, those who took a multi-vitamin pill did significantly better on word recall after one year (American J of Clin Nutr, May 24, 2023). After three years, they had the equivalent of three less years of memory loss than that which occurred in the placebo group. However, there was no difference between the two groups in memory retention, executive function, or object recognition.

The multi-vitamin pills contained vitamins D, A and B12, thiamine, riboflavin and manganese and more. Some of the authors of this study had found similar results in an earlier study on the subject (Alzheimer’s & Dementia Journal, Sept 22, 2022). Both studies showed that people with heart disease were the ones most likely to suffer memory loss.

Pros and Cons of Vitamin Pills to Help Prevent Memory Loss
The Alzheimer’s Association has not yet recommended the use of multivitamins to reduce the risk of cognitive decline in older adults. However, deficiencies of thiamine, B12 and D are associated with memory loss. You need stomach acid to absorb vitamin B12, so risk for vitamin B12 deficiency increases as people age because they lose stomach acidity. For more information, see my report on Vitamin B12: One Supplement You May Need. Vitamin B12 is found only in animals, not in plants, so vegetarians should take B12 supplements. I think that everyone should have their B12 level checked as they age. If B12 is below 300 pg/mL, your doctor may prescribe B12 pills, or order another blood test called homocysteine which is used to help diagnose vitamin B6, B9 or B12 deficiencies. People with elevated homocysteine levels are at increased risk for heart disease.

• U.S. dietary guidelines recommend getting nutrients from food, unless there are specific needs. Most physicians believe that it is better to get vitamins from food, rather than pills.
• Overdoses of some vitamins can harm you. Large doses of vitamins can cause side effects from stomach upset to serious heart and liver problems.
• Some of the investigators of these studies received grants from Mars Edge that produces the dietary supplement CocoaVia. Mars Edge and Pfizer Consumer Healthcare donated the multivitamins and placebo tablets and packaging.

My Recommendations
These good studies from respected researchers show possible benefits from taking vitamin pills, and no one has shown any harm from the small doses taken in a daily multi-vitamin. Whether or not you take multi-vitamins, I think that everyone should learn the rules for healthful living and follow a plant-based, anti-inflammatory diet, which has been shown to help prevent disease and prolong lives. Vegetarians and older people are at significant risk for vitamin B12 deficiency, so they should have blood vitamin B12 levels checked.