title: Sleep deprivation in the last trimester of pregnancy and inadequate vitamin D: Is there a relationship?
abstract: BACKGROUND
  Disturbed sleep is a significant health issue for pregnant women. Inadequate vitamin D intake is common among pregnant women and can affect many bodily systems. The purpose of this cross-sectional study was to test the hypothesis that serum vitamin D levels are low in pregnant women who have poor sleep quality in their last trimester.
  
  
  METHODS
  We enrolled 92 pregnant women who were admitted to the Maternity Clinic of Turgut Ozal University (Ankara, Turkey) in their last trimester. Venous blood sampling was performed to determine serum 25-hydroxyvitamin D levels. Sleep quality was measured by the Pittsburgh Sleep Questionnaire. The Student t test and Chi-square test were used to evaluate the relationships between variables. Logistic regression analysis was used to identify independent predictors of the vitamin D level.
  
  
  RESULTS
  The median score of the Pittsburgh Sleep Questionnaire was 6.2 ± 3.3 (range, 1-17). We determined that 43.5% (40) of participants had poor sleep quality. The mean number of sleep hours at night was 8.6 ± 1 hours (range, 6.30-11 hours), and the mean sleep latency was 20.3 ± 12.7 minutes (range, 5-60 minutes). Vitamin D levels were measured for 87 participants; the median serum level of 25 (OH) vitamin D was 22.9 ± 16.2 ng/mL (range, 4.9-99 ng/mL). Among all patients, we did not determine any significance between the vitamin D-deficient group and the non-vitamin D-deficient group with regard to the Pittsburgh Sleep Questionnaire Inventory (PSQI) total score and subcomponents scores of the questionnaire (p > 0.05). Among 37 patients with poor sleep quality and for whom the vitamin D level was measured, 56.8% (21) women had vitamin D deficiency, and 81% (30) women had vitamin D insufficiency. However, we did not find any significance between participants with poor sleep and participants with good sleep quality with regard to age, occupational status, relationship with her partner, prepregnancy body mass index (BMI), weight gain during pregnancy, being primiparus, length of labor, and mode of delivery. Our findings further showed that being in a low income family was associated with poor sleep quality.
  
  
  CONCLUSIONS
  Inadequate vitamin D and poor sleep quality are prevalent in pregnant women, but low levels of vitamin D are not associated with poor sleep quality. Further studies with larger sample sizes and studies that include preterm deliveries and special sleep disorders should be performed to understand this issue better.
authors.affiliation: Department of Pediatrics, Turgut Ozal University Faculty of Medicine, Ankara, Turkey. Electronic address: akinsuzan@gmail.com.
authors.forename: Suzan
authors.initials: S
authors.lastname: Gunduz
authors.affiliation: Department of Obstetrics and Gynecology, Turgut Ozal University Faculty of Medicine, Ankara, Turkey.
authors.forename: Hatice
authors.initials: H
authors.lastname: Kosger
authors.affiliation: Department of Psychiatry, Turgut Ozal University Faculty of Medicine, Ankara, Turkey.
authors.forename: Secil
authors.initials: S
authors.lastname: Aldemir
authors.affiliation: Department of Obstetrics and Gynecology, Turgut Ozal University Faculty of Medicine, Ankara, Turkey.
authors.forename: Banu
authors.initials: B
authors.lastname: Akcal
authors.affiliation: Private Kızıltepe Nisa Hospital, Sanlıurfa, Turkey.
authors.forename: Hatice
authors.initials: H
authors.lastname: Tevrizci
authors.affiliation: Department of Obstetrics and Gynecology, Turgut Ozal University Faculty of Medicine, Ankara, Turkey.
authors.forename: Deniz
authors.initials: D
authors.lastname: Hizli
authors.affiliation: Department of Biochemistry, Turgut Ozal University Faculty of Medicine, Ankara, Turkey.
authors.forename: Huseyin Tugrul
authors.initials: HT
authors.lastname: Celik
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000209:etiology*; D011263:Pregnancy Trimester, Third; D012893:Sleep Wake Disorders / Q000209:etiology*; D014808:Vitamin D Deficiency / Q000150:complications*
keywords: inadequate vitamin D; poor sleep quality; pregnancy