Dietary vitamin B6 intake and constipation in US adults
What it found
In a US survey of 3,643 adults, those who ate more vitamin B6 from food were less likely to report chronic constipation.
The study cannot show that vitamin B6 caused the difference.
What they found
Studies in people
Constipation rate
Of the 3,643 people studied, 270 (7.41%) had chronic constipation.
Higher intake, less constipation
People who took in more vitamin B6 from food were less likely to have constipation. The link stayed after accounting for factors like age, sex, race, BMI, drinking, smoking, income, diabetes and high blood pressure.
By intake group
Constipation was reported by 9.23% of people in the lowest vitamin B6 intake group, 8.15% in the middle group, and 4.85% in the highest group.
Subgroups
The link was seen in women, in Hispanic Black people, in people with high blood pressure, and in people with diabetes. Among smokers the link did not reach statistical significance.
Alcohol drinkers
Among people who drank alcohol, the link between higher vitamin B6 intake and lower constipation was significant.
Shape of the link
Curve fitting showed a straight-line downward link between vitamin B6 intake and constipation, rather than a curved one.
What the authors conclude
“This study found an inverse connection between vitamin B6 consumption and the prevalence of persistent constipation.”
Also in their conclusions
- They conclude that there is an inverse connection between vitamin B6 consumption and the prevalence of persistent constipation.
- They say that consuming more vitamin B6 through food may help to enhance intestinal motility and soften stool, which may help reduce constipation symptoms.
- They add that healthcare providers may consider dietary recommendations for patients with chronic constipation, pending further clinical trials, and that more extensive prospective trials are needed.
How it was done
The authors say not much research has looked specifically at whether vitamin B6 is linked to constipation, even though other dietary factors have been studied.
They used data from the 2009-2010 National Health and Nutrition Examination Survey, a US health and nutrition survey. They looked at 3,643 adults aged 20 and over, whose vitamin B6 intake from food was estimated from 24-hour diet recalls, and compared that with whether they had chronic constipation.
What it can’t tell you
- This was a cross-sectional survey, so it can show a link but not whether eating more vitamin B6 causes less constipation.
- Diet was recorded from 24-hour food recalls, which may not reflect what people usually eat over time.
- The findings come from US adults and may not apply to other populations.
Who paid
- Conflicts
- The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
- Authors work at
- Liaoning University of Traditional Chinese Medicine, China; Fujian Provincial People's Hospital, China
The paper
- Title
- Association between dietary vitamin B6 intake and constipation: a population-based study
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Liu X, Liu Y, Shu Y, et al (2024). Association between dietary vitamin B6 intake and constipation: a population-based study. Frontiers in nutrition. doi:10.3389/fnut.2024.1483515Free full textPubMed 39582668DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error