The Effect of Physical Activity on Vitamin D Levels and Improving Sleep Quality in Women

  Background & objectives: Vitamin D deficiency and poor sleep quality are important factors in health disorders and are common among women. The aim of this study was to investigate the effect of physical activity on vitamin D levels and improving sleep quality in women. Methods: This descriptive-analytical study was conducted on active and inactive women (85 individuals in each group), aged 30-48 years that were selected using convenience randomized sampling. The Pittsburgh Sleep Quality Questionnaire was used to assess sleep quality and a score higher than 5 was determined as poor sleep quality. For analysis of data, Kruskal Wallis and Mann Whitney U tests and Spearman coefficient were used at a significance level of 0.05. Results: The results showed that 54.12% and 28.82% of women had a deficiency and insufficient levels of vitamin D, respectively, and 61.8% had poor sleep quality. Active women had higher levels of vitamin D and better sleep quality compared to inactive women (p<0.05). There was also a direct relationship between vitamin D levels and sleep quality in active and inactive women. However, this association was significant in active women with vitamin D deficiency and inactive women with different vitamin D status. Conclusion: It seems that physical activity can increase vitamin D levels and improve sleep quality in women. But vitamin D status, especially its deficiency, may be one of the most important determinants of sleep quality in active and inactive women.