The Brazilian researchers call for further research to validate their findings and improve pregnant women’s mental and physical health.
“Solid evidence of the association between serum 25[OH]D concentrations allows for the formulation of practices and actions aimed at preventing maternal and fetal complications, identifying risk factors, and promoting early interventions, such as vitamin D supplementation,” they wrote.
They suggest that the findings could help identify women who are at higher risk for complications based on their vitamin D levels, allowing for targeted interventions.
Impact of vitamin D deficiency on pregnancy
The World Health Organization advises that Vitamin D deficiency is thought to be common among pregnant women in some populations and is associated with an increased risk of complications such as gestational diabetes, preterm birth, and pre-eclampsia.
A 2020 study of 34,417 pregnant women in Shanghai revealed that 9.9% of the population were severely vitamin D deficient, 60.1% were deficient, 28.4% were insufficient, and only 1.6% of the enrolled population reached adequate 25-hydroxyvitamin 25[OH]D levels of 75 nmol/L.
The current study cites previous research that shows that depression and anxiety are highly comorbid in the ante- and postnatal periods and notes that sociodemographic factors, behavioral aspects such as alcohol and smoking habits, and marital satisfaction can predict these conditions.
Additionally, current scientific efforts evaluate potential pathophysiological mechanisms related to these disorders, including the impact of vitamin D.
Fetal development and maternal mental health
Vitamin D is vital in gestation, and its metabolism is different from that of any other time in human physiology.
The fetus requires maintenance of higher concentrations of the active form of 25[OH]D to supply calcium. Studies show that vitamin D also regulates the immune system and inhibits inflammation during pregnancy.
However, vitamin D also plays a crucial role in mental health. It has receptors in the brain and is involved in hormone and neurotransmitter processes that affect mood regulation.
The current study's authors note that many factors can influence the vitamin D status of pregnant women, including latitude, season, diet, time spent outdoors, use of supplements, and clothing habits.
They hypothesize about potential mechanisms that impair mental health in the general population, including increased region-specific expression of brain receptors known to regulate mood, vitamin D's modulatory role in inflammation and depression, and its neuroprotective aspects.
“Thus, it is noteworthy that substantial attention should be given to individuals with reduced concentrations of 25[OH]D, such as pregnant women, as these may have more severe systemic and mental effects,” they wrote.
Vitamin D deficiency linked to depression in postnatal women
The researchers evaluated 6,769 eligible records that used valid methods to assess depression and anxiety symptoms and serum 25[OH]D levels in women during the ante/postnatal periods. From these records, they included 25 studies.
They found a significant difference in vitamin D levels in women with and without depression in both the ante and post-natal periods. Postnatal serum 25[OH]D concentrations were on average −2.36 ng/mL lower in women with postnatal depression than in those without.
They also found that anxiety symptoms in the antenatal period may not be associatedwith a low concentration of 25[OH]D, with only one study identifying a significant result.
The authors highlight the study's limitations and note that these should be considered when interpreting the findings. However, the study's strengths, including a vast literature screening, give a solid basis for future research to support women’s mental health during pregnancy.
Source: Nutrients 2024, 16(21), 3648; https://doi.org/10.3390/nu16213648
“Is serum vitamin D associated with depression or anxiety in ante- and postnatal adult women? A systematic review with meta-analysis”.
Authors: L.Centeno et al.