Association Between Three-Months Vitamin D Supplementation and Depressive Symptomatology incidence among Saudi Arabian Adults

Abstract

Objective: According to the World Health Organization (WHO), depression is the main cause of disability worldwide and high risk was noticed in Saudi Arabia. The link between nutrition and mental health has been extensively studied in recent years. Recently, vitamin D has been reported an important factor that may have significant health benefits in the prevention and the treatment of many chronic illnesses including mental Illness. In fact, vitamin D levels are linked to depressive symptomatology. Since Saudi Arabia have a high prevalence of depression and vitamin D deficiency and studies assessing this effect are still scarce, the aim of this study was to explore the relationship between Vitamin D supplementation and depressive symptomatology in Saudi Arabian Population. Methods: The present study is a 3-month randomized clinical trial of vitamin D supplementation performed in a weight loss clinic in Abha, Saudi Arabia. The study sample included 80 adults aged 18-65 years who were vitamin D deficient or insufficient. Participants were randomly allocated to receive either 50,000 IU vitamin D supplementation weekly for 3 months or to receive general dietary advice. The main outcome, depressive symptomatology was assessed using Patient Health Questionnaire-9 (PHQ-9). Serum 25(OH)D concentrations were measured in fasting venous blood samples. The analysis utilized Mann Whitney test, independent t-test, chi-square, Fisher’s exact, and ANOVA.Logistic regressions were performed to assess the relationship between vitamin D deficiency and prevalence of depression while adjusting for: age, gender, Body mass Index, Mediterranean Diet Adherence, and physical activity. Lastly, repeated measures were performed to check for the interaction between time and Vitamin D. Results: The final sample size included 71 participants with an average age of 30.23 ±7.66and constituted of 59.2% females. The mean baseline 25(OH)D3 concentration was 16.92±7.23ng/ml in the vitamin D group and 16.44±5.91 ng/ml in the control group (p =0.76). At baseline, when adjusting for age and gender only, we observed that lower vitamin D serum levels were associated with higher depression prevalence. When vitamin D was considered as continuous variable, each unit increase in vitamin D levels was associated with a lower depression prevalence (OR=0.87; 95% CI:0.79-0.95, p=0.005) and when compared to those insufficient, those deficient were 4 times more likely to suffer from depression (OR=4.47, 95% CI:1.39-14.38,p=0.012) Nevertheless, these significant results were lost with further adjustment for BMI, MeDi adherence and physical activity: continuous vitamin D: OR=0.90; 95% CI: 0.81-1.01, p=0.08, deficient versus insufficient:OR=2.18; 95% CI: 0.56-8.47,p=0.259). After three-months supplementation of 50,000IU, vitamin D levels increased to 51.41 ±11.27ng/ml in the supplemented group and to24.95 ±6.45ng/ml in placebo group (p=0.00). PHQ-9 scores decreased from 12.53 ±5.33 to 4.92 ±2.44 in vitamin D group (p <0.001), and from 12.46 ±4.66 to 8.96±3.75in the control group (p<0.001), indicating enhancement in depressive symptomatology. Furthermore, the change between both groups was significantly different (-7.61 ±4.03 in the Vitamin D group, -3.50±1.54 in the control group; p=<0.001) Conclusion: The present study shows thata 50.000 IU/week dose of vitamin D supplementation for 3 months was enough to increase vitamin D levels beyond sufficient and decrease depression symptoms in Saudi Arabian Adults. Nevertheless, future studies with larger sample size and longer duration are needed to determine if these benefits are long-term.