Scientists from Mount Sinai have found that low levels of folate (vitamin B9) in the blood may be linked to a substantially higher risk of dementia and death from any cause in older adults.
Folate is the natural, water-soluble form of vitamin B9 found in a variety of foods. It is also added to foods and sold as supplements in the form of folic acid, which is absorbed more efficiently—about 85% compared with around 50% from food sources.
Previous research shows that folate is essential for forming DNA and RNA, supporting protein metabolism, and breaking down homocysteine—an amino acid that can damage the body when present at high levels.
Folate also plays a key role in producing healthy red blood cells and is especially important during periods of rapid growth, such as pregnancy and fetal development.
However, the relationship between folate deficiency and dementia risk in older age has remained unclear.
In this study, researchers analyzed data from more than 27,000 adults aged 60–75 who had no diagnosis of dementia for at least 10 years. All participants had their folate levels measured and were then followed for the development of dementia or death.
The findings were striking: older adults with folate deficiency were 68% more likely to develop dementia and nearly three times more likely to die from any cause compared with those with adequate folate levels.
The researchers suggest that folate levels may serve as a useful biomarker to identify individuals at higher risk of dementia and mortality. However, they note that additional research is needed to determine exactly how folate deficiency might contribute to dementia risk.
Given the findings, the team recommends that folate deficiency be monitored and corrected in older adults to help reduce dementia risk.
The Recommended Dietary Allowance (RDA) for folate is expressed as dietary folate equivalents (DFE). Adults aged 19 and older should aim for 400 mcg DFE daily.
Pregnant people need 600 mcg DFE, while lactating individuals need 500 mcg DFE. Because alcohol can interfere with folate absorption, people who regularly drink alcohol should consume at least 600 mcg DFE per day.
The study was conducted by Anat Rotstein and colleagues and published in Evidence Based Mental Health.
