Vitamin D may be effective treatment for perinatal depression

Key takeaways:

• Elemental metals and polyunsaturated fatty acids, or PUFAs, do not seem to reduce perinatal depression.
• However, vitamin D offered small to medium effect size improvements.

Though popular dietary interventions that include polyunsaturated fatty acids, or PUFAs, and elemental metals do not seem to alleviate perinatal depression, vitamin D may be promising in this regard, according to researchers.

Dietary interventions are often used to treat anxiety and depression among people during pregnancy or up to 1-year postpartum, but data on their effectiveness is limited, Zoe Tsai, BHSc, an MD candidate at the University of Ottawa, and colleagues wrote in the American Journal of Clinical Nutrition.

Up to 20% of new mothers will face perinatal anxiety or depression, the researchers wrote, “with negative consequences for them, their offspring and their families.”

“Dietary interventions are perceived to be safe by many pregnant and postpartum persons, and nutritional imbalances have been hypothesized to be involved in the development and persistence of perinatal depression and/or anxiety, making them popular,” they wrote. “Considering the poor availability of psychotherapy and hesitation to take medication, there has been substantial interest in treatments that are considered ‘natural.’”

Tsai and colleagues conducted a systematic review and meta-analysis to evaluate how effective dietary interventions are for perinatal anxiety and depression treatment.

“Given over 89% of women reported taking any form of dietary intervention in their third trimester of pregnancy, it is important to evaluate whether dietary interventions are effective at treating perinatal depression and/or anxiety,” the researchers wrote.

Their study included 36 randomized controlled trials with a total of 7,010 participants, 28 of which were included in the meta-analyses.

Compared with control conditions, PUFAs did not seem to improve symptoms of perinatal depression (standardized mean difference = -11; 95% CI, -0.26 to 0.04) and those results did not change according to fatty acid ratio nor based on examination during pregnancy or the postpartum period, according to Tsai and colleagues.

The findings for elemental metals like iron, magnesium and zinc were similar (standardized mean difference = -0.42; 95% CI, -1.05 to 0.21). However, iron was beneficial for those with iron deficiency.

“Why PUFA supplementation does not appear to be superior to control conditions in the treatment of perinatal depression is not clear,” the researchers wrote. “Given the number of participants in this meta-analysis, it seems less likely that this is due to a lack of statistical power, but it is conceivable that differences in dosages or duration of administration could contribute to the variability among studies.”

On the other hand, vitamin D taken in daily doses of 1,800 to 3,500 international units offered small to medium effect size improvements for postpartum depression (standardized mean difference = -0.52; 95% CI, -0.84 to -0.2). However, further research is needed to assess causal interactions of dietary interactions on perinatal anxiety or depression.

Tsai and colleagues wrote that their findings “could be used to inform clinical practice guidelines and identify if dietary interventions are best suited for more or less severe cases, or as adjunct therapies with psychotherapy.”

“Given the findings on vitamin D dosages, additional evidence is also needed to determine the role of clinicians in recommending vitamin D supplementation during pregnancy or postpartum and monitoring potential excessive vitamin D intake in pregnant women,” they wrote.