Is Circulating Vitamin D Status Associated with the Risk of Venous Thromboembolism? A Meta-Analysis of Observational Studies.

BACKGROUND: Although vitamin D is antithrombotic, associations between serum vitamin D status and the risk of venous thromboembolism (VTE) remain inconsistent. METHODS: We searched the EMBASE, MEDLINE, Cochrane Library, and Google Scholar databases from inception to June 2022 to identify observational studies examining associations between vitamin D status and VTE risk in adults. The primary outcome presented as odds ratio (OR) or hazard ratio (HR) was the association of vitamin D levels with the risk of VTE. Secondary outcomes included the impacts of vitamin D status (i.e., deficiency or insufficiency), study design, and the presence of neurological diseases on the associations. RESULTS: Pooled evidence from a meta-analysis of sixteen observational studies, including 47648 individuals published from 2013 to 2021, revealed a negative relationship between vitamin D levels and the risk of VTE either based on OR (1.74, 95% confidence interval (CI): 1.37 to 2.20, p < 0.00001; I2 = 31%, 14 studies, 16074 individuals) or HR (1.25, 95% CI: 1.07 to 1.46, p = 0.006; I2 = 0%, 3 studies, 37,564 individuals). This association remained significant in subgroup analyses of the study design and in the presence of neurological diseases. Compared to individuals with normal vitamin D status, an increased risk of VTE was noted in those with vitamin D deficiency (OR = 2.03, 95% CI: 1.33 to 3.11) but not with vitamin D insufficiency. CONCLUSIONS: This meta-analysis demonstrated a negative association between serum vitamin D status and the risk of VTE. Further studies are required to investigate the potential beneficial effect of vitamin D supplementation on the long-term risk of VTE.

Factors Influencing the Compliance of Pregnant Women with Iron and Folic Acid Supplementation in the Philippines: 2017 Philippine Demographic and Health Survey Analysis.

Anemia in pregnancy, which is a public health concern for most developing countries, is predominantly caused by iron deficiency. At least, 180 days of iron and folic acid (IFA) supplementation is recommended for pregnant women to mitigate anemia and its adverse effects. This study aimed to examine compliance with the recommendation of IFA supplementation and its underlying factors using the 2017 Philippine National Demographic and Health Survey data. The variables assessed included age, highest level of education, occupation, wealth index, ethnicity, religion, residence, number of pregnancies, time of first antenatal care (ANC) visit and number of ANC visits. Compliance with the recommendation of at least 180 days of IFA supplementation was the outcome variable. The study assessed 7983 women aged 15-49 years with a history of pregnancy. Of these participants, 25.8% complied with the IFA supplementation recommendation. Multiple logistic regression analysis showed that pregnant women of Islamic faith and non-Indigenous Muslim ethnicity were less likely to comply with the IFA supplementation recommendation. Being aged between 25 and 34 years, having better education and higher wealth status, rural residency, initiating ANC visits during the first trimester of pregnancy and having at least four ANC visits positively influenced compliance with IFA supplementation. The effect of residence on IFA adherence differed across the wealth classes. Strategies targeted at specific groups, such as religious minorities, poor urban residents, the less educated and young women, should be strengthened to encourage early and regular antenatal care visits for improving compliance.