Vitamin D status should be explored to reduce anxiety, improve mental health
The study identified a pattern of sun avoidance and inadequate intake of vitamin D-rich foods resulting in high deficiency (65%) and high generalised anxiety disorder (GAD) scores among 386 study participants.
Age was another determining risk factor, while high levels of anxiety were also noted in students taking vitamin D (VTD) supplements (58%).
“The findings demonstrated a prominent association between sun avoidance and a low intake of vitamin D-rich foods and supplements on the one hand and anxiety on the other,” the authors wrote in Nutrients.
“This suggests that rectifying vitamin D levels may be a convenient, cost-effective, and low-risk method to improve anxiety and mental health status in general.”
Vitamin D effects
Sun deprivation is surprisingly common in UAE due to the hot and humid conditions that discourage outdoor activity; culture and religion also play a role as women are obliged to wear clothing that covers most of their body.
However, high avoidance reduces production of crucial hormones that regulate sleep, mood, and anxiety, thus the benefits for mental well-being cannot be ignored, the authors wrote.
“Sunlight exposure prompts the production of dermal nitric oxide and the release of serotonin and melatonin hormones in the brain. Nitric oxide helps to diminish anxiety and depression by alleviating inflammation and oxidative stress.”
The authors noted that vitamin D intake through diet can be difficult, given limited food sources and variable content, “further complicating the intake of sufficient amounts”. Furthermore, few studies have demonstrated the effectiveness of supplementation to alleviate symptoms, they said.
Study design
Researchers investigated the correlation between anxiety and vitamin D deficiency, citizenship, dietary and supplementary vitamin D intake, and sun exposure.
Healthy female students aged 18 and above were recruited from the University of Abu Dhabi using random and snowball sampling on social media. Of these, UAE nationals accounted for 74% of participants.
Within the study population, 65% were vitamin D deficient and 58% administered vitamin D supplements (between 1,000 to 50,000 IU weekly or 1,000 IU daily).
Participants completed food frequency questionnaires (FFQ), and sun avoidance inventory (SAI) and GAD data was collected. Further analyses were carried out to explore associations between general anxiety and vitamin D-related variables and to assess predictors of anxiety status.
Strong correlation
The majority of students (67%) returned GAD-7 scores above the cut-off, suggesting significantly high levels of anxiety among participants, the authors report.
Mean GAD-7 and SAI data (12 and 17 respectively) indicated high anxiety and sun avoidance across the study population, while the average FFQ score (10) determined global inadequacy of dietary vitamin D.
“The correlation analysis and multivariate logistic regression analysis to extrapolate associations with GAD demonstrated a significant correlation between anxiety symptoms and decreasing levels of dietary vitamin D intake and sun exposure,” they explained.
“This finding is in line with studies from other populations that also reported a similar relationship.”
Additional data confirmed a correlation between younger participants with a history of VTD deficiency, lower dietary VTD intake and sun exposure, and a higher risk of anxiety symptoms.
“According to our results, higher SAI and lower FFQ scores were strongly correlated with reported vitamin D deficiency and a greater risk for GAD. Moreover, a history of vitamin D deficiency was found to be associated with greater risks of GAD.”
Limitations and conclusion
The cross-sectional study does not confirm causation, the authors say, and as such results require validation. Moreover, the homogenous study population restricts generalisation of results.
They added: “Any conclusive results regarding the potential of vitamin D supplements for relieving symptoms of anxiety, more likely at the neurochemical level, should be interpreted with caution before compelling evidence is provided by additional RCTs and MR studies.”
Source: Nutrients
Published online, December 15, 2022: http://doi.org/10.3390/nu14245327
‘Associations between Dietary Intake of Vitamin D, Sun Exposure, and Generalized Anxiety among College Women’
Authors: F. Al Anouti, et al
