While past research has established a correlation between dietary micronutrient intake and the risk of developing constipation, the specific link between vitamin B intake and the bowel dysfunction remains largely unexplored.
To assess the association between chronic constipation and dietary vitamin B intake, researchers in China conducted a study based on National Health and Nutrition Examination Survey (NHANES) data collected between 2005 and 2010.
This included a total of 13,885 participants aged 20 and above, among which 1,043 individuals were classified as having constipation according to the Bristol Stool Form Scale (BSFS).
The participants completed the Bowel Health Questionnaire (BHQ) and reported their dietary intake via a 24-hour dietary recall interview.
The analysis revealed a non-linear inverse correlation between dietary intake of all examined B vitamins (vitamins B1, B2, niacin, B6, folate, choline, and B12) and risk of constipation.
In particular, a significant reduction in constipation risk was observed in the highest intake quartiles of niacin (p = 0.003), folate (p < 0.001), and choline (p = 0.05), even after adjusting for multiple confounding variables.
Subgroup analyses further indicated that alcohol consumption significantly modified the relationship between folate, vitamin B1, niacin, choline, and constipation.
“Increased dietary intake of B vitamins may contribute to a reduced risk of constipation, particularly among specific population subgroups. These results offer a scientific foundation for the potential application of B vitamins in constipation management.
“Healthcare providers could also consider dietary interventions as a non-pharmacological approach to support patients affected by chronic constipation,” the researchers wrote.
Dietary regulation
Epidemiological studies have stated that constipation has a prevalence of approximately 10.1% among adults, with higher rates observed among older individuals and women.
The primary risk factors have been identified to be dietary habits, socioeconomic status, lifestyle choices, levels of physical activity, medication usage, and mental health conditions such as depression.
Among these, diet is a modifiable factor that has garnered interest for both constipation prevention and management.
Previous studies have suggested that inadequate fluid intake and excessive consumption of dietary saturated fat and energy may increase constipation risk, whereas a high intake of soluble fibre, selenium, and an overall high-quality diet may lower it.
Since the human body cannot produce most B vitamins on its own, they must be obtained through dietary sources. And while the gut microbiota can synthesise some B vitamins, this contribution is generally insufficient to meet requirements.
Abundant in foods such as vegetables, grains, legumes, nuts, meat, and eggs, B vitamins are water-soluble vitamins essential for various metabolic processes.
They also play a key role in intestinal health by supporting the growth and maintenance of intestinal cells, modulating the enteric nervous system that controls intestinal movement, regulating gut microbiota, attenuating intestinal inflammation, maintaining immune homeostasis, and influencing overall gut function.
Furthermore, B vitamin intake may indirectly mitigate constipation risk by improving overall dietary quality.
“Individuals with constipation often exhibit poor dietary patterns characterised by insufficient B vitamin intake and lower Healthy Eating Index (HEI)-2015 scores. Notably, higher HEI-2015 scores have been linked to a reduced risk of constipation
“Individuals with higher HEI-2015 scores were found to consume greater amounts of fibre- and water-rich foods, such as fruit, vegetables, whole grains, and legumes. Both dietary fibre and adequate water have been demonstrated to alleviate constipation effectively.”
As vitamin B12 in animal products, such as meat and dairy, is produced by microorganisms in the animal’s intestines, a diversified diet incorporating various food categories is said to adequately fulfil the requirements for most B vitamins in healthy individuals.
Although the present study adjusted for multiple confounders, factors such as gut microbiota composition, medication use, and underlying conditions like hypothyroidism that can affect gut function, were not fully accounted for.
“Future prospective clinical trials should be performed to evaluate the therapeutic efficacy of B vitamin supplementation in constipation management.
“Additionally, further study is vital to clarify the specific mechanisms through which B vitamins influence intestinal motility and to assess their effects under varying dietary and lifestyle conditions. The role of personalised dietary interventions should also be explored to optimise their practical application,” the researchers concluded.
Source: Frontiers in Nutrition
https://doi.org/10.3389/fnut.2025.1594644
“Evaluating the link between the dietary intake of vitamin B and constipation: a population-based study”
Authors: Wenyuan Yang, et al
