Body mass index and serum folate in childbearing age women

Background: Higher pre-pregnancy body mass index (BMI) is associated with increased risk of neural tube defects (NTDs) and possibly other negative birth outcomes in the offspring. The mechanism for this association remains unknown. Lower maternal folate level has been implicated in the etiology of NTDs in general. The association of BMIwith folate level, however, has not been investigated. Methods: The present study examines the association of BMI with folate level in childbearing age women before and after the 1998 U.S. folate fortification program of cereal products, using data from two cross-sectional surveys of theU.S. population, the third wave of the NationalHealth and Nutrition Examination Survey (NHANES III; 1988–1994) and the more recent wave of this survey (NHANES 1999–2000). Results: After controlling for intake of folate in food and nutritional supplements, increased BMI in childbearing age women was associated with a lower serum folate level in both surveys (p < 0.001). Using data from NHANES 1999–2000, it was estimated that women in the 30.0+ kg/m² BMI category would need to take an additional 350 g/day of folate to achieve the same serum folate level as women in the < 20.0 kg/ma₂ category. Conclusion: Lower folate level may be one mechanism linking higher maternal BMI and increased risk of NTDs in the offspring. If corroborated in future studies, findings from this study suggest a need for a higher dose of folate supplement in heavier childbearing age women.     

Low vitamin D status in preschool children in Greece

Vitamin D status in humans depends on the amount of sun exposure and vitamin D intake. Recent reports suggest that hypovitaminosis D (as defined by serum 25-hydroxyvitamin D [25(OH)D] <10 ng/mL) is reemerging in developed countries and in the Middle East, pointing out the significance of dietary and cultural practices. In the line of prevention, we determined vitamin D status in 393 healthy preschool children randomly selected from 7 day care centers in the Municipality of Athens in October. The data for the analysis were collected from a questionnaire regarding their actual dietary practices, voluntary sun exposure, and lifestyle conditions; clinical investigation for the determination of the skin phototype; and blood sampling for the determination of serum 25(OH)D, parathyroid hormone, and osteocalcin levels. Of the 393 children, 49 were immigrants. According to our results, 6.6% of our population had serum 25(OH)D less than 10 ng/mL. Multilinear analysis showed that the amount of sun exposure and vitamin D intake were the direct determinants of vitamin D status. Immigrant children presented lower serum 25(OH)D levels associated with lower vitamin D intake and lower socioeconomic class when compared with the Greek children. No relationship was found between 25(OH)D concentration and skin phototype, whereas 93.3% of children used topical sunscreen. We suggest that abundant sunlight exposure in Athens is not sufficient to prevent hypovitaminosis D in preschool children. The extensive use of topical sunscreens and environmental factors such as air pollution would account for inadequate sunlight exposure and the need for dietary intake of vitamin D.     

冬季妊娠中期孕妇25-羟维生素D的营养状况

目的 探讨冬季妊娠中期孕妇的25-羟维生素D[25(OH)D]营养状况及其与孕妇年龄、血红蛋白水平的相关关系。方法 选取2009年12月至2010年2月在南京医科大学第一附属医院就诊的78名正常妊娠中期孕妇为研究对象。于孕24 ～ 28周取空腹静脉血,检测血清25(0H)D和全血血红蛋白水平。采用Pearson相关分析研究血清25(OH)D水平与孕妇年龄、血红蛋白水平的相关性。结果 冬季妊娠中期孕妇25(OH)D缺乏(≤25.0 nmol/L)的发生率为65.38％,25(OH)D不足[25.0 nmol/L＜25 (OH)D≤50.0 nmol/L]的发生率为30.77％,25(OH)D正常者占3.85％。冬季妊娠中期孕妇血清25(OH)D水平与血红蛋白水平呈正相关(r=0.2746,P=0.015)。结论 冬季妊娠中期孕妇普遍存在25(OH)D不足或缺乏,低血红蛋白水平的孕妇尤甚。     

Associations of Vitamin D Intake with 25-Hydroxyvitamin D in Overweight and Racially/Ethnically Diverse US Children

Overweight children and minorities are at risk of vitamin D deficiency. Little information exists on whether overweight children and minorities who do not meet dietary vitamin D recommendations are at risk for low 25-hydroxyvitamin D (25OHD) status. Vitamin D intake from foods and dietary supplements was estimated in 3,310 children/adolescents who were examined as part of the 2005-2006 National Health and Nutrition Examination Survey. Weight status was dichotomized into healthy weight or overweight/obese. Parent-reported race/ethnicity was categorized as non-Hispanic white, non-Hispanic black, Mexican American, or other. Adjusted logistic regression was used to determine whether children who did not achieve the Estimated Average Requirement (EAR) were at increased risk for inadequate 25OHD. Nearly 75% of children failed to meet the EAR. Overall, not meeting the EAR was associated with inadequate 25OHD (odds ratio=2.5; 95% CI 1.4 to 4.5). However, this association differed by weight status (P=0.02) and race/ethnicity (P=0.02). Overweight/obese children who failed to meet the EAR were five times more likely to be at risk for inadequate 25OHD than overweight/obese children who met it (95% CI 2.0 to 12.7; P<0.001). Non-Hispanic blacks with intakes below the EAR were nearly four times more likely to be at risk for inadequate 25OHD than those who met the EAR (95% CI 1.5 to 9.7; P<0.01). The majority of US children failed to meet current vitamin D recommendations. Overweight/obese and non-Hispanic black children were especially likely to be at risk for inadequate 25OHD when not consuming the EAR.     

Prevalence of vitamin D insufficiency in Canada and the United States: importance to health status and efficacy of current food fortification and dietary supplement use

Several recent studies have identified a surprisingly high prevalence of vitamin D insufficiency in otherwise healthy adults living in Canada and the United States. Most striking are the effects of latitude, season, and race. Also noteworthy is that dietary vitamin D is not reaching the population in greatest need, nor is it very protective against insufficiency. Fluid milk, as the predominant vehicle for vitamin D fortification, is apparently not very effective in staving off vitamin D insufficiency in adults in all populations at all times of the year.     

中国育龄女性GC基因rs7041多态性与血清维生素D水平的关联

目的探究中国18~44岁育龄女性维生素D结合蛋白编码基因GC rs7041位点与血清维生素D水平的关联。方法从2015年中国成人慢性病与营养监测生物样本库中分层随机选取涵盖31个省的18~44岁1812名育龄女性的血液样本,采用酶联免疫法测定血清25-羟基维生素D[25(OH)D]含量,多重高温连接酶检测反应技术进行GC基因分型。结果共纳入1812名育龄女性,所有样本rs7041基因型频率分布符合Hardy-Weinberg平衡定律。血清25(OH)D水平[M(P25,P75)]为16.69(12.04,21.69)ng/mL。在总体样本及南方地区,维生素D正常人群中CC基因型携带者的25(OH)D水平显著高于AA基因型(P<0.05)。校正可能的相关影响因素前后,携带CC基因型个体发生维生素D不足的风险均明显低于AA基因型个体(OR=0.571,95%CI 0.373~0.873))。亚组分析结果显示,无论处于南方或北方,该基因型携带者维生素D缺乏的风险均较低[南北方校正后的OR值分别为0.284(95%CI 0.144~0.560)和0.109(95%CI 0.015~0.798)]。结论 GC rs7041位点A/C多态性与中国育龄女性血清25(OH)D水平显著相关,纯合突变型CC可能为维生素D缺乏或不足风险的保护因素。     

Vitamin D status and hypertensive disorders in pregnancy

PurposeSeveral studies have reported increased risk of preeclampsia when 25-hyrdoxyvitamin D (25[OH]D) levels are low. The extent to which 25(OH)D may lower risk for hypertensive disorder during pregnancy remains unclear.MethodsAmong women enrolled in the Project Viva prenatal cohort in Massachusetts, we examined associations of 25(OH)D levels obtained at 16.4–36.9 weeks of gestation (mean 27.9 weeks) with hypertensive disorders of pregnancy, including preeclampsia (56/1591, 3.5%) and gestational hypertension (109/1591, 6.9%).ResultsWe did not detect an association between plasma 25(OH)D concentration (mean 58, standard deviation 22 nmol/L) and preeclampsia. For each 25 nmol/L increase in 25(OH)D, the adjusted odds ratio for preeclampsia was 1.14 (95% confidence interval, 0.77–1.67). By contrast and contrary to hypothesis, higher 25(OH)D concentrations were associated with higher odds of gestational hypertension: adjusted odds ratio for gestational hypertension was 1.32 (95% confidence interval, 1.01–1.72) per each 25 nmol/L increment in 25(OH)D. Vitamin D intake patterns suggest that this association was not because of reverse causation. Although the elevated hypertension risk may be due to chance, randomized trials of vitamin D supplementation during pregnancy should monitor for gestational hypertension.ConclusionsThese data do not support the hypothesis that higher 25(OH)D levels lower the overall risk of hypertensive disorders of pregnancy.     

The potential role of vitamin D enhanced foods in improving vitamin D status

Low vitamin D intake and status have been reported worldwide and many studies have suggested that this low status may be involved in the development of several chronic diseases. There are a limited number of natural dietary sources of vitamin D leading to a real need for alternatives to improve dietary intake. Enhancement of foods with vitamin D is a possible mode for ensuring increased consumption and thus improved vitamin D status. The present review examines studies investigating effects of vitamin D enhanced foods in humans and the feasibility of the approach is discussed.     

Alexithymia is associated with low level of vitamin D in young healthy adults

Objective

Vitamin D plays an important role in brain development and functioning. Low levels of vitamin D have been described in several psychiatric and neurologic conditions including autism spectrum disorder. Alexithymia that shows high comorbidity with autism is also present in the general population as well as hypovitaminosis D.

Methods

Here we assessed the relation between alexithymia as measured by the Toronto Alexithymia Scale-20 and vitamin D level in healthy young adults.

Results

We found an inverse correlation between the levels of alexithymia and vitamin D.

Discussion

These data suggest the association between disturbed emotional processing and low levels of vitamin D to be present in young healthy subjects.     

城市居民维生素D营养状况调查

目的调查分析浙江2城市居民维生素D营养状况。方法选取杭州、宁波2城市,按多阶段整群随机抽样方法,采集442名居民的血样,采用放射免疫法进行血清25羟维生素D[25（OH）D]检测,分析2城市居民维生素D营养状况。结果 6岁-、12岁-、18岁-、45岁-和60岁-组血清中25（OH）D中位数分别为53.19（41.85-64.89）、48.76（32.56-60.52）、59.91（48.05-72.79）、68.67（55.50-78.07）和70.97（56.91-84.65）nmol/L。居民维生素D缺乏、不足、正常和适宜人数分别占2.95%、30.84%、44.22%和22.00%。结论所调查的2城市居民维生素D缺乏状况普遍,维生素D营养状况有待改善。     

Evidence of low vitamin D intakes in the Australian population points to a need for data-driven nutrition policy for improving population vitamin D status

Background

Nearly one in four Australian adults is vitamin D deficient (serum 25-hydroxyvitamin D concentrations [25(OH)D] < 50 nmol L^–1) and current vitamin D intakes in the Australian population are unknown. Internationally, vitamin D intakes are commonly below recommendations, although estimates generally rely on food composition data that do not include 25(OH)D. We aimed to estimate usual vitamin D intakes in the Australian population.

Methods

Nationally representative food consumption data were collected for Australians aged ≥ 2 years (n = 12,153) as part of the cross-sectional 2011–2013 Australian Health Survey (AHS). New analytical vitamin D food composition data for vitamin D₃, 25(OH)D₃, vitamin D₂ and 25(OH)D₂ were mapped to foods and beverages that were commonly consumed by AHS participants. Usual vitamin D intakes (µg day^–1) by sex and age group were estimated using the National Cancer Institute method.

Results

Assuming a 25(OH)D bioactivity factor of 1, mean daily intakes of vitamin D ranged between 1.84 and 3.25 µg day^–1. Compared to the estimated average requirement of 10 µg day^–1 recommended by the Institute of Medicine, more than 95% of people had inadequate vitamin D intakes. We estimated that no participant exceeded the Institute of Medicine's Upper Level of Intake (63–100 µg day^–1, depending on age group).

Conclusions

Usual vitamin D intakes in Australia are low. This evidence, paired with the high prevalence of vitamin D deficiency in Australia, suggests that data-driven nutrition policy is required to safely increase dietary intakes of vitamin D and improve vitamin D status at the population level.     

老年人血浆维生素K和D水平的季节变化

目的了解老年人群血浆维生素K和维生素D水平的季节变化。方法对85名健康老年人用放射免疫分析法测定春秋两季血浆维生素D(25(OH)D)和甲状旁腺素(PTH)含量,用高压液相色谱法测定血浆维生素K含量。结果血浆维生素K水平女性在春秋两季均明显高于男性,而男性和女性各自无季节性差异。无论男女秋季血浆维生素(25(OH)D)水平明显高于春季,同一季节内男女间差异无统计学意义。维生素D缺乏率女性春季为63.4%,秋季为7.3%。男性春季为65.9%,秋季无缺乏者。春季维生素D缺乏率显著高于秋季(P<0.05)。男女秋季血浆PTH浓度明显低于春季。老年女性春季血浆25(OH)D浓度和血浆PTH浓度之间呈负相关(r=-0.426,P<0.001)。结论该人群血浆25(OH)D和PTH有明显的季节变化,春季血浆25(OH)D水平低。而血浆维生素K没有季节变化。     

微量血清中25-羟维生素D的柱前衍生-高效液相色谱-串联质谱法的建立及其临床应用

目的 建立微量血清中25-羟维生素D2（25-(OH)D2）和25-羟维生素D3（25-(OH)D3）的高效液相色谱-串联质谱法（LC-MS/MS）,并用于临床常规检验。方法 10微升血清样本中加入同位素内标,用无水乙醇沉淀蛋白再用正己烷萃取,氮气吹干后衍生,复溶后经液相色谱分离、质谱定性定量。结果 25-(OH)D2和25-(OH)D3的线性相关系数（r）分别为0.9958和0.9937;批内精密度小于13.2%,批间精密度小于11.9%,平均加样回收率均在93.6%~109.7%之间;25-(OH)D2和25-(OH)D3的LOD分别为0.1ng/ml和0.025ng/ml,LOQ分别为1.5ng/ml和5ng/ml。在所检测的213份血样中约有6%的儿童的25-羟维生素D低于15ng/ml。结论 本法满足方法学要求,可用于微量血清中25-羟维生素D2和25-羟维生素D3的测定,对儿科临床诊断治疗有重要提示意义。     

The effect of body mass index on adequacy of serum 25-hydroxyvitamin D levels in US adults: the National Health and Nutrition Examination Survey 2001 to 2006

PurposeTo investigate the relationship between body mass index (BMI) and vitamin D adequacy among US adults.MethodsWe used data for US adults aged 18 years or older (n = 12,927) who participated in the 2001 to 2006 United States National Health and Nutrition Examination Survey. Log-binomial regression was used to estimate the strength of association between BMI categories and the prevalence of serum 25-hydroxyvitamin D [25(OH)D] greater than or equal to 20 ng/mL before and after controlling for selected characteristics. An interaction term between race or ethnicity and BMI categories was tested.ResultsAmong US adults, 67.2% had serum 25(OH)D greater than or equal to 20 ng/mL, a cut point suggested by the Office of Dietary Supplements for adequate bone and general health. Overweight and obese adults were 8% (95% confidence interval, 0.89–0.95) and 26% (95% confidence interval, 0.71–0.78), respectively, less likely to have serum 25(OH)D greater than or equal to 20 ng/mL than their normal weight counterparts after controlling for age, gender, race/ethnicity, nativity and marital status, as well as education and income. No heterogeneity of the association between BMI categories and the prevalence of 25(OH)D greater than or equal to 20 ng/mL was observed by race or ethnicity.ConclusionsThe low prevalence of 25(OH)D greater than equal to 20 ng/mL among overweight and obese adults in the US population underscores the need to comparatively assess vitamin D intakes across different BMIs.     

Effects of sun exposure and dietary vitamin D intake on serum 25-hydroxyvitamin D status in hemodialysis patients

BACKGROUND/OBJECTIVES

Vitamin D deficiency is common in hemodialysis patients. The aim of this study was to identify whether or not sun exposure and dietary vitamin D intake have effects on serum 25-hydroxyvitamin D (25(OH)D) status in hemodialysis (HD) patients. The objective was to identify the main determinants of serum vitamin D status in the study subjects.

SUBJECTS/METHODS

A cross-sectional study of 47 HD patients (19 males and 28 females) was performed. We assessed serum 25(OH)D and 1,25(OH)₂D levels between August and September 2012 and analyzed the prevalence of vitamin D deficiency in HD patients. To evaluate the determinants of serum 25(OH)D levels, we surveyed dietary vitamin D intake, degree of sun exposure, and outdoor activities. To compare biological variables, serum 25(OH)D was stratified as below 15 ng/ml or above 15 ng/ml.

RESULTS

Mean 25(OH)D and 1,25(OH)₂D levels were 13.5 ± 5.8 ng/ml and 20.6 ± 11.8 pg/ml, respectively. The proportions of serum 25(OH)D deficiency (< 15 ng/ml), insufficiency (15-< 30 ng/ml), and sufficiency (≥ 30 ng/ml) in subjects were 72.4%, 23.4%, and 4.3%, respectively. Prevalence of vitamin D deficiency in female patients was 78.6%, whereas that in males was 63.2% (P = 0.046). Vitamin D intake and sun exposure time were not significantly different between the two stratified serum 25(OH)D levels. Dietary intake of vitamin D did not contribute to increased serum 25(OH)D levels in HD patients. The main effective factors affecting serum 25(OH)D status were found to be the sun exposure and active outdoor exercise.

CONCLUSIONS

Hypovitaminosis D is common in HD patients and is higher in females than in males. Sun exposure is the most important determinant of serum 25(OH)D status in HD patients.     

沈阳地区婴幼儿维生素D营养状况的调查研究

目的 了解沈阳地区0～3岁婴幼儿维生素D(VitD)营养状况与其性别、年龄以及季节的关系,为本地区婴幼儿合理进行VitD的补充提供科学依据。方法 对沈阳市妇婴医院儿童保健门诊体检的0～3岁婴幼儿,采用化学发光法进行血清25(OH)D水平检测。结果 2 381例婴幼儿25(OH)D总体平均水平为(36.73±18.75)ng/ml,其中25(OH)D水平严重缺乏组8例(0.34%)、缺乏组174例(7.31%)、不足组149例(6.55%)、正常组2 026例(85.09%)、过量组24例(1.01%);不同性别间血清25(OH)D水平差异无统计学意义(P＞0.05);0～1岁婴儿组血清25(OH)D水平低于1～3岁幼儿组,两组差异有统计学意义(P＜0.05);不同季节婴幼儿血清25(OH)D水平冬季最高,春季最低。结论 沈阳地区0～3岁婴幼儿VitD的总体营养状况较好,但仍存在VitD缺乏及过量现象。应注重科学合理补充VitD,避免出现VitD不足、过量及中毒情况。     

生殖发育状况对绝经妇女体质指数的影响分析

目的:研究生殖发育状况对绝经后妇女体质指数的影响。方法:通过多阶段分层整群随机抽样的方法,采用自行设计的调查表,由经过统一培训的调查员对泸州地区年龄在30～70岁(包括30岁和70岁)的妇女进行问卷调查。结果:绝经妇女平均体质指数为23.9,其中超重占34.0%,肥胖占11.1%。月经初潮年龄、首次怀孕年龄以及绝经原因是绝经妇女体质指数的影响因素。结论:女性的生殖发育过程与其体质指数有密切关系,有助于发现超重、肥胖的高危人群。