*3.8. Minerals*

The minerals that were assessed for an impact on anxiety symptoms in animal models most frequently are zinc, magnesium, manganese, and selenium (Figure 11). The animal studies reported a largely consistent anti-anxiety effect from supplementing these nutrients. The observational studies assessing tissue levels of magnesium most frequently reported no association with anxiety levels or anxiety disorder prevalence. Observational studies assessing tissue levels of zinc reported a combination of protective effects and no association while the observational studies assessing selenium primarily reported an association between higher intake and lower symptom severity. A small number of observational studies reported an association between higher copper or sodium and increased anxiety symptoms or disorder prevalence.


**Figure 11.** Studies assessing minerals and anxiety. ■ Higher intake or levels associated with decreased anxiety. ■ No association between intake or levels and anxiety. ■ Higher intake or levels associated with increased anxiety.

> A limited number of intervention studies have delivered minerals in supplemental form, including selenium, zinc, magnesium, iron, copper, and calcium. All four studies that administered selenium supplements reported improvement in anxiety symptoms. Studies administering other minerals reported a mixture of anti-anxiety effects and no effect. Only one experimental study included participants with anxiety disorders [45]. This open label study provided zinc to 38 participants for eight weeks and reported an improvement in anxiety symptoms.
