Prevalence of vitamin D deficiency in the pregnant women: an observational study in Shanghai, China

Abstract

Background Maternal vitamin D deficiency has been a worldwide concern in recent years. However the epidemiological data of vitamin D deficiency among large group of Chinese pregnant women is limited. This study is to evaluate the prevalence of vitamin D deficiency among pregnant women in Shanghai, China and to analyze the association of vitamin D status with some pregnancy outcomes (gestational diabetes and low birth weight). Methods A total of 34,417 pregnant women in Shanghai were included in this study from January 2014 to December 2017, and the serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured at 16th week of gestation by electrochemiluminescence assay. Seventy five grams of glucose was used to conduct oral glucose tolerance test during 24-28th week of gestational in all enrolled persons and the birth weight of newborns was recorded. Results The median serum 25(OH) D concentration in the pregnant women during 4 years was 42.87 nmol/L (32.88–51.90 nmol/L). 9.9% of the population were severe vitamin D deficient [25(OH)D < 25 nmol/L], 60.1% were deficient [25 nmol/L ≤ 25(OH)D < 50 nmol/L], 28.4% were insufficient [50 nmol/L ≤ 25(OH)D < 75 nmol/L] and only 1.6% of the enrolled population reached the level of adequate [25(OH)D ≥ 75 nmol/L]. Serum 25(OH) D concentrations showed significant difference among seasons with the highest level in winter and the lowest level in summer. Women with advanced maternal age were more likely to have better vitamin D status compared with younger women. The 25(OH) D levels were significantly different among 2014–2017. The year of 2017 had the highest 25(OH) D level with the median serum concentration reaching 47.80 nmol/L (41.00–55.00 nmol/L), while the lowest appeared in 2016 which has median 25(OH) D concentration at 38.87 nmol/L (28.76–49.97 nmol/L). No relations were found between the 25(OH) D status and the rate of gestational diabetes or low birth weight of newborns. Conclusion Pregnant women in Shanghai were generally deficient in vitamin D status and the level of vitamin D was related to season and age. No evidence showed vitamin D deficiency in pregnant women contributes to the rate of gestational diabetes or low birth weight of newborns in this study. These results suggest that most of the pregnant women may need vitamin D supplementation to achieve adequate vitamin D level.

Vitamin D status and vitamin D deficiency risk factors among pregnancy of Shanghai in China

“…Our study found that the level of vitamin D of Chinese pregnant women in Shanghai was 16 (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21) ng/ml, and 31.8% (303) pregnant women had severe vitamin D deficiency; 40.7% (388) had vitamin D deficiency; 25.1% (239) had vitamin D insufficiency; only 2.4% (23) had normal vitamin D; None were found to have vitamin D above 50 ng/ml. Our study found that the level of vitamin D increased with age groups (t = 8.5, p = 0.04); Vitamin D deficiency decreased with age groups (X 2 = 17.6, p = 0.04).…”

“…A few studies on vitamin D deficiency in Chinese pregnant women are after 20 weeks of pregnancy. Such as, the vitamin D deficiency rate (< 20 ng/ml) of pregnant women in Wuxi of China is 90% at 23–28 weeks of gestation [ 30 ], and the vitamin D deficiency rate (< 20 ng/ml) is 94.7% in Nanjing of China [ 31 ], and 90.2% in Beijing [ 21 ]. Our study population was a selected group of pregnant women who visited the outpatient clinic for their first prenatal examination when 12–14 weeks of gestation of Chinese pregnant women in Shanghai.…”

“…Shanghai is one of the largest cities in China with more than 20 million people, and it is the location of East China at 31 degrees north latitude. Recent evidence suggests that pregnant women in Shanghai were generally deficient in vitamin D status [ 20 , 21 ], from 90.5% to 98.4% of these women had serum 25(OH)D levels below 30 ng/mL and the causes of high vitamin D deficiency among high-risk groups in this region remain insufficiently known.…”

The Association between Vitamin D Status and Autism Spectrum Disorder (ASD): A Systematic Review and Meta-Analysis

“…Considering the importance of vitamin D and the high prevalence of vitamin D deficiency, regular screening of vitamin D levels in autistic individuals and necessary intervention are recommended. Furthermore, pregnant and lactating women consume more vitamin D than usual and are generally deficient in vitamin D [ 66 ]; maternal and neonatal vitamin D status may be associated with subsequent diagnosis of ASD. Vitamin D status should be included in routine screening during pregnancy and lactation in order to provide appropriate clinical intervention.…”

Assessment of vitamin D supply in children of Moscow and the Moscow Region

“…Во всем мире существует проблема низкой информированности родителей о роли витамина D в организме, источниках его поступления, последствиях дефицита и организации профилактического приема препаратов витамина D. При этом лишь каждый 4-й ребенок в возрасте до 2 лет получает профилактическую дозу холекальциферола [17]. Большинство взрослых также не осведомлены и не принимают витамин D [18][19][20][21].…”