Thiamin intake linked to less constipation in US adults
What it found
In a survey of 10,371 US adults, those who ate more thiamin (vitamin B1) were less likely to report chronic constipation.
This kind of study can show a link, not cause and effect.
What they found
Studies in people
Constipation rate
Out of 10,371 people, 1,123 (10.8%) had chronic constipation. Constipation was defined by stool consistency or having fewer than 3 bowel movements a week.
Higher intake, less constipation
People who ate more thiamin were less likely to have constipation. In the fully adjusted analysis, the link remained.
Groups by intake
When people were split into three groups by thiamin intake, the highest group had less constipation than the lowest group. The rates were 14.09%, 10.70% and 7.69% from lowest to highest.
Subgroups
The link was strongest in men, and in people without high blood pressure or diabetes. The authors note there was no significant interaction between these groups.
Other findings
Possible reasons
The authors suggest thiamin may help soften stools and increase bowel movements. They point to its role in energy metabolism, gut nerves and muscles, neurotransmitters, and antioxidant effects.
What the authors conclude
“In summary, our study reveals a negative correlation between dietary vitamin B1 consumption and the prevalence of chronic constipation among the general adult populace.”
Also in their conclusions
- They conclude that there is a negative correlation between dietary vitamin B1 intake and chronic constipation in US adults.
- They suggest that eating more vitamin B1 may soften stools and increase intestinal movement, which could ease constipation.
- They advise healthcare professionals to promote a balanced diet as a first treatment step before medical treatments.
How it was done
The authors say the link between constipation and vitamin B1 had not been studied before. They wanted to look at whether eating more vitamin B1 goes with less chronic constipation in adults.
They used data from NHANES, a US health and nutrition survey run between 2005 and 2010. They looked at 10,371 adults aged 20 or older, whose diets were recorded using 24-hour dietary recalls, and compared thiamin intake with whether they had chronic constipation.
What it can’t tell you
- This was a cross-sectional survey, so it cannot show whether low thiamin intake causes constipation or constipation leads to eating less thiamin.
- Diet was recorded from 24-hour recalls, which may not reflect long-term eating habits.
- The study relied on people reporting their own bowel habits and food intake.
Who paid
- Conflicts
- The authors declare no competing interests.
- Authors work at
- The Affiliated Stomatological Hospital of Soochow University, China; Wuxi People's Hospital Affiliated to Nanjing Medical University, China; Maternal and Child Health Care Hospital of Kunshan, China
The paper
- Title
- The association between dietary vitamin B1 intake and constipation: a population-based study
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Du W, Lu L, Liu Y, et al (2024). The association between dietary vitamin B1 intake and constipation: a population-based study. BMC gastroenterology. doi:10.1186/s12876-024-03255-2Free full textPubMed 38760704DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error