Demographic and Lifestyle Factors Associated with Vitamin D Status in Pregnant Japanese Women

Abstract

Vitamin D has drawn attention as a significant nutrient to prevent pregnancy complications and health problems in offspring (1, 2). For instance, maternal vitamin D deficiency has been speculated to cause endothelial dysfunction, a key feature of preeclampsia, through a proinflammatory response and increase in oxidative stress (3). Its deficiency also leads to low birth size through the inhibition of bone mineral accrual of the fetus (4).Maintaining maternal circulating 25-hydroxyvitamin D (25(OH)D) concentrations above 30.0 ng/mL is recommended (5). However, the high ratio of severe vitamin D deficiency (25(OH)D,10.0 ng/mL) in pregnant women is a significant concern in many countries (6-8). In Japan, two studies showed that the mean serum 25(OH)D concentrations during pregnancy were only 9.5-14.5 ng/mL (9, 10). The concentrations were especially lower in winter. To improve the vitamin D status of pregnant Japanese women, identification of populations at a high risk of vitamin D deficiency and implementation of appropriate intervention are necessary. In general, vitamin D status depends on vitamin D intake (vitamin D21D3) and vitamin D3 production in the skin through exposure to sunlight (11). Although vitamin D status was reported to be affected by age, body mass index (BMI), physical activity, and season (12-15), factors associated with vitamin D status vary with the target population and latitude. Among pregnant Australian women, low serum 25(OH)D concentrations were significantly predicted by non-Caucasian, high BMI, non-use of vitamin D supplements, and winter season (14). Among non-pregnant Japanese women, young age, low dietary vitamin D intake, low walk counts, and long sedentary activity time correlated with low serum 25(OH)D concentrations (16,17). The walk counts and sedentary activity time were presumed to reflect the amount of exposure to sunlight. However, it remains unclear which factors are associated with vitamin D status in pregnant Japanese women, the extent to which those factors are associated with vitamin D status, and whether the factors vary with the season.The objective of the present study was to examine demographic and lifestyle factors associated with

Vitamin D deficiency during pregnancy and its associated factors among third trimester Malaysian pregnant women

“…Only one in three women in the study were taking dietary supplements containing vitamin D, such as multivitamins and calcium supplements enriched with vitamin D. Intake of supplements containing vitamin D significantly lowered the risk of vitamin D deficiency in the bivariate model but was no longer significant in the multivariate model. This finding was inconsistent with previous studies conducted among pregnant Japanese [32] and Chinese [38] women, in which the use of vitamin D supplements and multivitamins were associated with higher serum 25(OH)D levels. One of the possible explanations for these findings is that the use of vitamin D supplements was uncommon among Malaysian pregnant women.…”

“…In this study, pregnant women who had higher intake vitamin D were more likely to have lower risk of vitamin D deficiency. This finding is in agreement with Shiraishi et al [32] that found higher vitamin D intake significantly contributed to higher serum 25(OH)D concentration among pregnant women. This could be attributed to the high consumption of vitamin D containing food such as milk and milk products and fish and fish products (as shown in Table 3).…”

Pre-pregnancy BMI and intake of energy and calcium are associated with the vitamin D intake of pregnant Malaysian women

“…In addition, women in Malaysia tend to reduce sunshine exposure due to covered dress (religious practice) or use of sunscreen for either cosmetic reasons or to prevent skin damage [38,39]. The use of sunscreen could block UV light and subsequently inhibit vitamin D production [40]. Moreover, nearly all (98%) pregnant women in the present study were housewives and indoor workers (data not shown), which could contribute to them having a lower duration of sun exposure.…”

Hypovitaminosis D in pregnancy: Is it a public health issue?

“…Being primigravida was associated to a lower mean of concentration of vitamin D, a higher percentage of hypovitaminosis D and a lower percentage of vitamin D sufficiency, which was in agreement with the results from other authors. 20,[23][24][25] Pregnant adolescents had a higher percentage of hypovitaminosis D. Perhaps pregnant adolescents may tend to be more withdrawn and participate in fewer outdoor activities or even have less adherence to prenatal recommendations. Studies have shown that this age group seems to be more vulnerable to vitamin D deficiency.…”