09/06/2026
How much folate is too much?
Our latest publication explores this important—and often overlooked—question in maternal and child health.
👉 Read the paper: https://www.rbmojournal.com/article/S1472-6483(25)00447-X/fulltext
This systematic review, led by Dr Carolyn Ledowsky, examines the effects of excess folic acid intake and elevated folate levels during preconception and pregnancy.
Folic acid has been one of the great public health success stories in preventing neural tube defects—but our findings suggest the picture is more complex when intake goes beyond optimal levels.
Across 45 studies, we found consistent evidence that higher folic acid exposure may be linked to an increased risk of gestational diabetes, with clear dose–response patterns.
The review also highlights potential links with:
• Higher birthweight and increased likelihood of large-for-gestational-age infants
• Differences in child neurodevelopment (including attention and cognition), with some signals at very high exposures
• Maternal outcomes such as gestational hypertension and poorer fertility or IVF outcomes in some contexts
At the same time, not all findings are consistent—and importantly, there is currently no clear definition of what counts as “too much” folate.
Overall, this work highlights the need to move beyond a simple “more is better” approach. Instead, we need clearer guidance on safe upper limits, better ways of measuring folate status, and more awareness of total intake from diet, supplements, and food fortification.
As fortification and supplementation remain key public health strategies, it’s critical we understand both the benefits and the potential unintended consequences.
