Is there a Relationship between Postpartum Depression and Inadequate Vitamin D in the Last Trimester?

Research Article

Austin Med Sci. 2016; 1(1): 1004.

Is there a Relationship between Postpartum Depression and Inadequate Vitamin D in the Last Trimester?

Gunduz S¹*, Kosger H², Akcal B², Tevrizci H³, Hizli D², Aldemir S4 and Namuslu M5

¹Department of Pediatri, Turgut Ozal University Faculty of Medicine, Turkey

²Department of Obstetrics and Gynecology, Turgut Ozal University Faculty of Medicine, Turkey

³Private Kızıltepe Nisa Hospital, Turkey

4Department of Psychiatry, Turgut Ozal University Faculty of Medicine, Turkey

5Department of Biochemistry, Turgut Ozal University Faculty of Medicine, Turkey

*Corresponding author: Suzan Gunduz, Department of Pediatri, Turgut Ozal University Faculty of Medicine, Alpaslan Turkes Street No: 57, Emek, Ankara,Turkey

Received: March 22, 2016; Accepted: April 28, 2016; Published: May 03, 2016


Objectives: Vitamin D insufficiency is common among pregnant women especially in their last trimester and it can be related to Postpartum Depression (PPD).

Materials and Methods: This study was conducted in Turgut Ozal University Maternity Clinic. Vitamin D levels measured at 36th gestational week of pregnancy and at 6th. week of postpartum Edinburg Postnatal Depressive Scale (EPDS) was filled in.

Results: The mean ± SD level of serum 25 (OH) D vitamin was 22.9 ± 16.2 ng/mL. Between participants with vitamin D insufficient and sufficient groups, age of mother, feeding type, EPDS scores were not statistically significant. The mean ± SD score of EPDS was 9.5 ± 5.3. A good relationship with the partner, low crying hour per day, breast feeding and formula feeding together and high weight gaining of baby per month were associated with low EPDS scores.

Conclusion: Although there is a high frequency of vitamin D insufficiency among pregnant women, no association between vitamin D level in the last trimester and PPD. A significant difference between feeding type of the infant, relationship with the partner, crying hour of the infant and infant’s weight gain through a month and PPD.

Keywords: Postpartum depression; Vitamin D; Postnatal depression; Pregnancy


Portpartum Depression (PPD) is defined as a non-psychotic depressive episode that starts in the postpartum period. It is a public health problem estimated to affect 10-15% of women world wide and can develop at any time during the first postpartum year [1,2]. In Turkey, 15% - 40% of mothers suffer from PPD symptoms [3,4]. However, almost half of the suffering mothers ignore and deny the symptoms of depression and choose not to seek professional help [5]. PPD affects not only the life of the women themselves, but it can also affect their families and their infants’ growth and development [6].

Postpartum depression occurs mostly in young, lowersocioeconomic status women. Most commonly reported risk factors are past history of depression or other psychiatric illness, recent life stress, child care stress, difficult infant temperament and fatigue [2,7].

Vitamin D can be synthesised in the skin through exposure to Ultraviolet B (UV B) light and a small amount is obtained through dietary intake. Sunlight exposure is often the major influence on vitamin D status, but vitamin consumption can also strongly affect it [8]. Vitamin D level is also influenced by skin colour, latitude, season, lifestyle and cultural practices.

Once ingested or produced by the body, vitamin D3 is transported to the liver for hydroxylation to 25-Hydroxyvitamin D3 (25(OH) D), the main circulating form of vitamin D and the best measure of vitamin D status, and then to the kidney where the active hormonal form of vitamin D; 1,25(OH)2D, is produced. Maternal 25(OH)D is thought to freely cross the human placenta [9].

Recently, the Institute of Medicine defined adequate vitamin D status as having serum 25 (OH) D vitamin concentrations greater than 50 nmol/L (or 20 ng/mL) in both the general population and pregnant women [10]. Many investigators consider that optimal levels should be greater than 75 nmol/L or 30 ng/mL [11]. Current guidelines define vitamin D deficiency as serum levels of 25(OH)D below 20 ng/mL, insufficiency as serum levels between 20 and 32 ng/ mL, and sufficiency as serum levels greater than 32 ng/mL, although there is debate whether this level may need to be increased to 40 ng/ mL [12]. In pregnancy, vitamin D deficiency and insufficiency are also common. It has been suggested that a supplemental dose of vitamin D of 1000 or 1600 IU/day (25 to 40 mikrogram/day) might be necessary to achieve the optimal level [12].

In May 2011, the Turkish Ministry of Health suggested vitamin D 1200 IU/day (30 microgram/day) for 6 months prepartum and 6 months postpartum, totalling 12 months, to safely improve pregnancy and infant outcomes [13]. The biological mechanism linking vitamin D and mood disorders is still unclear. In the emerging literature examining the role of 25(OH) D in depression, vitamin D has been termed a ‘neurosteroid’ for its effect on brain function [14]. Active vitamin D enhances glutathione metabolism in neurons, thereby promoting antioxidant activities that protect those cells from oxidative degenerative processes [15]. Vitamin D deficiency has also been linked to altered brain morphology and may regulate gene expression of tyrosine hydroxylase, an enzyme involved in the synthesis of neurotransmitters such as norepinephrine and dopamine [15]. It also could be related to the location of Vitamin D Receptors (VDRs) within the brain. VDRs are inadequately occupied in the presence of vitamin D deficiency (25(OH) D <20 ng/mL), which may interfere with proper functioning of hormonal processes that prevent disease within the brain, such as mood disorders [12].

Prediction of postpartum depression and treatment of vitamin D deficiency/insufficiency can prevent PPD and this is very important for the benefit of the mother and also her children. This exploratory study was conducted to determine whether a longitudinal relationship exists between symptoms associated with postpartum depression and inadequate vitamin D in the last trimester.

In the literature, vitamin D has been measured in the first or second trimester. However, in the last trimester vitamin D levels may change by factors such as consumption of foods rich in vitamin D or by sunshine. This is the first study measuring vitamin D levels in the last trimester (36th gestational week) and its association with PPD.

Material and Methods

Study design

This small cohort study was conducted in the Turgut Ozal University Maternity Clinic between 1st January 2013 and 1st July 2013, with 92 women satisfying the inclusion criteria.

The sample size was estimated to detect a minimum clinically significant difference of the association between vitamin D level and postpartum depression to have 80% power with 5% type I error level. The estimated sample size was 79 patients.

The study was approved by the Fatih University Medical School Ethics Committee, and written informed consent was obtained from all participating mothers.

Study population

Participants met all of the following inclusion criteria: aged 18 to 45 years, delivered an infant who was at least 37 weeks gestation, having singleton pregnancy, not having systemic or psychological disease, and having taken a vitamin supplement (500 IU/day vitamin D) throughout the pregnancy.

Blood sample

Pregnant women who were in the 36th gestational week, had their blood sampled for 25 (OH) vitamin D. These venous blood samples were centrifuged at 4000 rpm/minute for 10 minutes and serum was collected and stored at -80 °C. Serum 25 (OH) vitamin D concentrations were analyzed by high-performance liquid chromatography (Shimadzu - DGU-20A3, Kyoto, Japan).

Serum 25(OH)D3 levels <20 ng/mL (50 nmol/L) were classified as vitamin D deficient, and < 32 ng/mL (75 nmol/L) as vitamin D insufficiency.

Measure of depressive symptoms

The Edinburg Postnatal Depressive Scale (EPDS) was used to measure depressive symptoms 6 weeks after delivery. The EPDS is a 10-item, self-rating questionnaire developed to screen for depression in the postpartum period; it addresses symptoms present during the previous seven days. The scale consists of 10 short statements with responses scored as 0, 1, 2, or 3 and takes approximately 5 minutes to complete. A cut off of 10 or above was found to have good psychometric properties for a diagnosis of depression [1,16]. The linguistic and pilot studies in order to be able to apply EPDS to Turkish women were conducted [17].

Other study factors

Maternal data: The demographic information collected included maternal age and occupation, gravida and parity, relationship with the partner, number of previous children, prepregnancy BMI, weight gain in the pregnancy, and having a helper at home.

Infancy data: The information collected included mode of delivery, gestational age, any complications in childbirth, APGAR score, 1 month old weight gain and feeding status, and crying hours in a day.

Statistical analyses

SPSS version 16.0 (SPSS, Chicago, IL, USA) for Windows program was used for statistical analyses. Kolmogorov-smirnow test was used to determine normal distribution. Descriptive statistics were presented as mean and Standard Deviations (SD) for not normally distributed data, and as counts and percentages for categorical data. Normally distributed and with homogeneous variances groups were compared two groups by Student’s t test. Mann-Whitney test was used for data not normally distributed. Chi-squared test was used to evaluate relationship between categorical variables. A Spearman correlation coefficient and its’ significance was calculated for the association between PPD and vitamin D level. A logistic regression analysis was performed to determine the independent effects of vitamin D on PPD. The Hosmer-Lemeshow goodness of fit test was also performed. The statistical significance level was set at P <0.05.


A total of 92 women with the age of 30.4 ± 4.6 years between the range of 18 and 40 were recruited in this study. More than half of them are house wife and nearly three-quarters of women have helper, and 67.4% of them have good relationship with their partner.

Blood samples of five participants missed, so we studied 87 blood samples for vitamin D level.

The mean ± SD of EPDS score assessed 6 weeks after delivery in 92 women was 9.5 ± 5.3 with the range of 0 and 25. The mean ± SD of vitamin D level measured at 36th gestational week in 87 women was 22.9 ± 16.2 ng/mL with the range of 4.9 and 99.

The characteristics of the mothers studied and their children are shown in (Table 1).