Researchers in China analyzed UK Biobank data to examine the association between dietary biotin intake and anxiety and depression, assess the dose–response relationship and evaluate whether inflammation mediates this association.
The results suggested that “higher dietary biotin intake may act as a protective factor against anxiety and depression,” the researchers wrote in Frontiers in Nutrition.
Inflammation and cognitive wellness
Research has shown that micronutrients such as vitamin D, vitamin B12, magnesium and biotin may protect against mental disorders such as anxiety and depression.
Biotin, also known as vitamin B7, plays a role in metabolic processes and regulates oxidative stress and inflammation, both of which are strongly linked to poor cognitive health. Some early-stage research showed that biotin reduces anxiety- and depression-like behaviors by modulating inflammatory and oxidative pathways.
The researchers on the new study suggest that low biotin levels may increase inflammation and oxidative stress, which can affect brain function and contribute to anxiety and depression. Biotin may also influence mitochondrial function and amino acid metabolism, further affecting mental health.
Biotin and the UK Biobank cohort
For their study, the Chinese researchers examined data from the UK Biobank prospective cohort study, which enrolled adults between the ages of 40 to 69 across 22 assessment centers in the UK between 2006 and 2010.
Biotin intake was assessed using a validated online 24-hour dietary recall questionnaire, where participants reported consumption of approximately 200 food and beverage items. Biotin intake was then calculated using standardized portion sizes and nutrient values from the UK Nutrient Databank.
Participants with pre-existing anxiety or depression were excluded, and throughout the study, and new cases of anxiety and depression that emerged throughout the trial period were identified using medical records. The researchers assessed data from participants from baseline until diagnosis, death, failure to follow-up, or Sept. 30, 2023.
They assessed inflammation using data on blood biomarkers, including C-reactive protein and white blood cell–related measures, and several combined inflammation indices. They included information on age, sex, lifestyle, socioeconomic status, diet quality, body mass index and chronic disease history in their assessement.
Finally, the researchers analyzed the association between dietary biotin intake and anxiety and depression using regression models, adjusted for potential confounders. They performed subgroup, sensitivity, and mediation analyses to test whether inflammation explained part of the association.
Study finds higher biotin intake may support mental well-being
Results showed that higher biotin intake was consistently associated with a lower risk of anxiety and depression. Compared to participants in the lowest biotin group, those in higher intake groups had a reduced risk of anxiety alone, depression alone and anxiety–depression comorbidity.
The researchers reported that inflammation partially explained the association between biotin intake and anxiety-related outcomes, as several inflammatory markers and composite inflammation scores mediated the relationship between biotin and anxiety or anxiety/depression combined.
The relationship between biotin intake and mental health outcomes however, was non-linear: While risk decreased as biotin intake increased, it reached its lowest level at around 45–47 μg/day and then leveled off.
Sex-specific analysis showed that the biotin inflection point occurred at 40–42 μg/day in males and 45–48 μg/day in females, indicating that higher biotin levels are required to exert a protective effect in males compared to females.
Males also showed higher levels of oxidative stress and baseline inflammation than females. The researchers therefore suggest that males may need a higher intake of biotin to adequately activate anti-inflammatory and antioxidant pathways against anxiety and depression.
“Based on these findings, the present study may offer preliminary insights for informing future recommendations regarding Recommended Nutrient Intake (RNI),” the researchers concluded. “It also suggests that consideration could be given to setting a higher RNI for males compared to females.”
They added that the study only examined inflammatory markers as mediators, however other mechanisms may also explain the effects of biotin on anxiety and depression, warranting further investigation.
Source: Frontiers in Nutrition. doi: 10.3389/fnut.2025.1745340. “Associations of dietary biotin intake on anxiety and depression: findings from a population-based prospective cohort study”. Authors: Y. Kong et al.
