Folic acid and chemotherapy side effects in colorectal cancer
What it found
In 290 people with colorectal cancer having capecitabine chemotherapy, taking folic acid supplements or having folic acid in the blood was linked to more treatment changes due to side effects.
Folate from food and blood folate levels showed no such link.
What they found
Studies in people
Treatment changes
153 of 290 patients (53%) had toxicities that led to a change in their capecitabine treatment.
Folate intake and levels
Folate intake and plasma folate levels were not linked to the risk of toxicities.
Folic acid supplements
Using folic acid-containing supplements during treatment was linked to an increased risk of toxicities.
Folic acid in blood
Having folic acid in plasma at diagnosis and during treatment was linked to an increased risk of toxicities.
What the authors conclude
- They suggest a potential association between folic acid and capecitabine-induced toxicities.
- They say this provides a rationale to study diet-drug interactions and raise further awareness of the use of dietary supplements during oncological treatment.
How it was done
Capecitabine works by blocking an enzyme involved in folate metabolism, and there are concerns that high intakes of certain vitamins, especially folate, during chemotherapy might affect treatment toxicity. It was unclear whether folate or folic acid affect treatment toxicity.
They followed 290 patients with stage II to III colorectal cancer receiving capecitabine within the COLON cohort. Dietary and supplemental folate and folic acid intake were assessed at diagnosis and during chemotherapy using questionnaires for 280 patients, and plasma folate and folic acid levels were measured for 212 patients. Toxicities were defined as treatment changes such as dose reductions, regimen switches, or early discontinuation.
What it can’t tell you
- We summarised it from the abstract only.
- This was an observational cohort study, so it can show links but cannot prove that folic acid causes the treatment changes.
- It cannot rule out other differences between patients that might explain the results.
Who paid
- Authors work at
- Wageningen University & Research, the Netherlands; Hospital Gelderse Vallei, the Netherlands; Northumbria University, United Kingdom
The paper
- Title
- Intake and biomarkers of folate and folic acid as determinants of chemotherapy-induced toxicities in patients with colorectal cancer: a cohort study
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Kok DE, van Duijnhoven FJ, Lubberman FJ, et al (2024). Intake and biomarkers of folate and folic acid as determinants of chemotherapy-induced toxicities in patients with colorectal cancer: a cohort study. The American journal of clinical nutrition. doi:10.1016/j.ajcnut.2023.11.023PubMed 38070682DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error