B vitamins and anxiety
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B Vitamins and Anxiety: Associations and Evidence
B Vitamin Intake and Anxiety Risk
Multiple studies have found that low intake or deficiency of certain B vitamins is linked to higher anxiety levels. Specifically, lower dietary intake of vitamin B6, B12, and biotin has been associated with increased odds of anxiety symptoms in adults and adolescents 149. In large population studies, higher intake of biotin, thiamin, niacin, and pantothenic acid was related to lower odds of anxiety, with biotin showing the strongest association, especially in women 14. Similarly, vitamin B6 deficiency was linked to a higher risk of anxiety in older adults .
Sex Differences in B Vitamin Effects on Anxiety
Some research suggests that the relationship between B vitamin intake and anxiety may differ by sex. For example, one study found that the negative association between vitamin B12 and methionine intake and anxiety was significant in males but not in females, possibly due to hormonal differences . Another study reported that higher vitamin B6 intake was associated with lower anxiety risk in women but not in men .
B Vitamin Supplementation and Anxiety Symptoms
Randomized controlled trials and systematic reviews have examined whether B vitamin supplementation can reduce anxiety. While some trials show that B vitamin supplementation can improve overall mood and reduce stress, the evidence for a direct effect on anxiety symptoms is mixed. Meta-analyses indicate that B vitamin supplementation may benefit stress but does not consistently reduce anxiety in healthy or at-risk individuals . However, high-dose vitamin B6 supplementation has been shown to reduce anxiety in some experimental settings .
B Vitamins, Neurobiology, and Mechanisms
B vitamins play important roles in brain function, including neurotransmitter synthesis and the regulation of neural excitation and inhibition. Deficiencies in B vitamins can disrupt these processes, potentially leading to increased anxiety 25. Animal studies have shown that B vitamin supplementation can reduce anxiety-like behaviors, possibly by suppressing neuroinflammation and oxidative stress in the brain .
B Vitamins, Anxiety, and Other Mental Health Conditions
While most studies focus on the protective effects of B vitamins, one Mendelian randomization study suggested that higher serum vitamin B12 levels might be associated with an increased risk of anxiety disorders, though this finding requires further validation and may be influenced by genetic or population-specific factors .
B Vitamin Status, Fortified Foods, and Prevention
Regular intake of B vitamin–fortified foods has been associated with a reduced risk of depression and may help optimize B vitamin status, which could contribute to better mental health and potentially lower anxiety risk, especially in older adults .
Conclusion
Overall, evidence suggests that adequate intake of B vitamins—especially B6, B12, and biotin—may be linked to lower anxiety risk, with some differences observed between men and women. While supplementation may help reduce stress and, in some cases, anxiety, the effects are not consistent across all studies. Maintaining good B vitamin status through diet or fortified foods appears beneficial for mental health, but more research, especially randomized controlled trials, is needed to clarify the specific effects on anxiety.
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