A recent study published in the Journal of Dietary Supplements found high dose vitamin D supplementation is associated with decreased depression, but not aggression, among teenage girls.
Approximately 20% of teens develop depression before they reach adulthood. By the age of 16 years, girls are much more likely become depressed than boys. There are a variety of factors that may contribute to one’s risk of depression, including physical health, life events, genetic predisposition, environmental factors and biochemical imbalances.
Common symptoms of depression include, but are not limited to:
- Feelings of sadness
- Social withdrawal
- Changes in sleep or appetite
- Difficulty focusing
- Low energy
- Frequent crying
- Feelings of worthlessness
- Suicidal thoughts
Vitamin D plays an important role in many physiological processes throughout the body, including the brain. In fact, vitamin D receptors have been found in many parts of the brain linked to depression. Additionally, vitamin D helps regulate serotonin and dopamine, which are neurotransmitters responsible for feelings of well being and sleep quality. Low levels of dopamine and serotonin are believed to be major contributors to the development of depression.
Research evaluating the relationship between vitamin D and depression is continuing to grow. Overall, research suggests that a link exists between vitamin D status and depression. Unfortunately, clinical trials have produced conflicting findings regarding whether vitamin D supplementation helps treat depression. Additionally, no studies to date have evaluated the relationship between vitamin D and aggressive behavior, a common symptom of depression.
Therefore, researchers conducted a clinical trial to evaluate the efficacy of high-dose vitamin D supplementation on treating depression and aggression among adolescent girls between 13 and 16 years of age. Individuals were excluded from the study if they had chronic diseases (aside from depression), were taking anti-inflammatory medication, antidepressants, antidiabetic or anti-obesity drugs, vitamin D, calcium or received hormone therapy within the past 6 months. A total of 988 girls fit the criteria, and thus were included in the study.
The participants received 50,000 IU (1,250 mcg) vitamin D3 weekly for a total of 9 weeks. At baseline and completion of the intervention, the participants received the following assessments:
- Anthropometric measurements: assessed the patient’s overall physical and cardiovascular health
- Beck Depression Inventory (BDI): a self-reported questionnaire used to measure depression severity. A higher BDI score indicates greater severity of depression.
- Buss-Perry Aggression Questionnaire: used to quantify the participant’s aggressive tendencies, with a higher score indicating greater aggression.
Here is what the researchers found:
- A total of 940 of the 988 girls completed the intervention.
- Depression score was significantly associated with aggression score at baseline (p < 0.001).
- Average vitamin D levels significantly improved from 6.69 ng/ml at baseline to 35.45 ng/ml at completion of the intervention (p = 0.001).
- Vitamin D supplementation was associated with a significant reduction in depression score (p = 0.001), but not aggression score.
The researchers concluded,
“…Our results indicate that vitamin D supplements at a dose of 50,000 IU once a week for 9 weeks can improve depression scores in adolescent girls.”
This study provides further evidence supporting the importance of maintaining healthy vitamin D status for managing depression. The researchers noted the study’s limitations. Due to the relatively short study duration, the researchers were unable to determine the long term effects of vitamin D supplementation. Additionally, the lack of a placebo group left the study at risk for response bias.
The researchers stated,
“Further studies with a follow-up phase are necessary to identify the long-term effects of this vitamin on mood disorders.”
Sturges, M. High dose vitamin D supplementation may help reduce depression among adolescent girls. The Vitamin D Council Blog & Newsletter, 8/2017.