What is the Relationship Between Pregnancy Symptoms, Vitamin D Status, and Quality of Life?

Friday, 28 July 2017: 3:10 PM

Jennifer G. Woo, MSN, BSN
Louise Herrington School of Nursing, Baylor University, Dallas, TX, USA


There is much evidence in the literature about vitamin D deficiency and associated symptoms such as depression, musculoskeletal pain, sleep disorders, pelvic floor disorders and fatigue, all of which can be present in pregnancy (Spedding, 2014; Aydogmus et al., 2014; McCarty et al., 2013; Bergstrom et al., 2014). However, these observational studies have mainly examined this correlation in the non pregnant population, aside from a handful of studies that have shown this correlation in pregnant women. Since pregnant women are so at risk for vitamin D deficiency, the study of this group is warranted (Hossein-Nezhad & Holick, 2013; Wagner et al., 2012; Ginde et al., 2010)

However, whether low levels of vitamin D are associated with these and other symptoms during pregnancy is unknown. What is known is that vitamin D deficiency disproportionately affects pregnant minority women, therefore, this study will help nurses, providers, etc.to understand the impact that vitamin D deficiency has on pregnancy symptoms and potential impact on quality of life (Ginde et al., 2010).

Therefore, the purpose of this study is to describe the pregnancy symptoms of a vulnerable patient population at risk for vitamin D deficiency and other poor maternal outcomes. In addition to describing the pregnancy symptoms that most frequently occur in this patient population, their impact on quality of life is also addressed.

Methods:  This study utilized a correlational, cross- sectional design and recruited women from an urban, underserved, low income health center. The participants (n=125) were 50 % African American, 42% Hispanic, and 8% other. Women were 24 to 32 weeks gestation and were attending the center for routine healthcare at the time of consent and data collection. They completed demographic, pregnancy symptom questionnaire (Pregnancy symptom Inventory), and quality of life (SF-12) questionnaires, which were available in English and Spanish. At the same visit, they had a blood draw to measure vitamin D levels [25 hydroxy vitamin D= 25 (OH) D ]. Women were classified using Institute of Medicine guidelines of < 20 ng/ml as deficient and ≥ 20 ng/ml being sufficient.


The sample composed of 125 pregnant women with a mean age of 26.7 years of age and 60% of sample being multiparous women (n=75) and 40% primiparous (n=50). The pregnancy symptoms reported by at least 70% of all women included: tiredness, urinary frequency, food cravings, back pain, headache, and poor sleep. However, the participants had to rate the limitation in their activities of daily living for each of the pregnancy symptoms they reported on the questionnaire (42 total symptoms on the PSI). The pregnancy symptoms that caused the most limitation varied slightly from those that were most frequently reported. The symptoms that had the most impact on activities of daily living were: tiredness, poor sleep, back pain, and hip/pelvic pain. There was a discrepancy noted from the symptoms that were most frequently occurring and those that impacted their daily living. For example, urinary frequency was listed as the second most commonly reported symptom, but it only caused limitation to daily living 35% of the time. On the other hand, hip/pelvic pain was reported as the ninth most frequently reported symptom by 66% of women, yet it was the fourth highest symptom causing limitations in daily living. A Mann Whitney U analysis was used to compare group differences of limitation of the top 60% of symptoms reporting limitation to activities of daily living between women who had vitamin D levels < 20 ng/ml (deficient based on IOM standards) and ≥ 20 ng/ml (sufficient based on IOM standards) in their pregnancy symptoms. Significant differences were found for tiredness, poor sleep, back pain, and hip/pelvic pain based on their rating of the effect on their limitation on activities of daily living with p values < .05 with a Bonferroni correction due to risk of inflated type I error.

In addition, women who had higher total pregnancy symptoms scores (sum score of all their pregnancy symptoms) had poorer quality of life as measured by SF-12. There was a significant negative correlation between physical component score and total pregnancy symptom total score (r = -0.31, p < .001). Thus, women who had higher pregnancy symptom scores had worse physical functioning. Similarly, there was a significant negative correlation between mental component score and pregnancy symptom total score (r = -0.32, p < .001) indicating that women who had higher pregnancy symptom scores had worse mental health.

Conclusion:  Based on the results of the study, vitamin D status may potentially impact pregnancy symptoms such as back pain and poor sleep. These symptoms can significantly affect health and quality of life. These findings also suggest that exploration of the association between vitamin D levels and pregnancy symptoms is warranted in a larger sample which could then be followed by a supplementation study to determine its effectiveness in treating these symptoms during pregnancy.