Vitamin D status and associated factors of deficiency among Jordanian children of preschool age.

BACKGROUND/OBJECTIVES: Vitamin D deficiency in children remains a global concern. Although literature exists on the vitamin D status and its risk factors among children in the Middle East, findings have yielded mixed results, and large, representative community studies are lacking. SUBJECTS/METHODS: In a nationally representative survey of 1077 Jordanian children of preschool age (12-59 months) in Spring 2010, we measured 25(OH)D3 concentrations by liquid chromatography-tandem mass spectrometry and calculated prevalence ratios for deficiency associated with various factors. RESULTS: RESULTS showed 19.8% (95% confidence interval (CI): 16.4-23.3%) deficiency (<12 ng/ml) and 56.5% (95% CI: 52.0-61.0%) insufficiency (<20 ng/ml). In adjusted models, prevalence of deficiency was higher for females compared with males (prevalence ratio (PR)=1.74, 95% CI: 1.22-2.47, P=0.002) and lower for children 24-35 months of age (PR=0.64, 95% CI: 0.44-0.92, P=0.018) compared with children 12-23 months of age. In rural areas, there was no difference in prevalence of vitamin D deficiency between those whose mothers had/did not have vitamin D deficiency (P=0.312); however, in urban areas, prevalence of vitamin D deficiency was 3.18 times greater among those whose mothers were vitamin D deficient compared with those whose mothers were not deficient (P=0.000). CONCLUSIONS: Vitamin D deficiency and insufficiency pose significant public health problems in Jordanian children with female children disproportionately affected. Strong associations between vitamin D status in children and urban residency and maternal vitamin D status suggest that the behaviors related to sun exposure in urban mothers likely also affect the sun exposure and thus vitamin D status of their children.

An empiric evaluation of the Institute of Medicine's pregnancy weight gain guidelines by race.

OBJECTIVE: To examine associations between pregnancy weight gain outside and within ranges recommended by the Institute of Medicine and birth weight by both prepregnant body mass index (BMI) and race-ethnicity. METHODS: Mean birth weight and incidence of term low birth weight (LBW, less than 2500 g) and high birth weight (more than 4500 g) were compared across BMI-pregnancy weight gain-race-ethnicity strata. Subjects were 173,066 white, black, and Hispanic low-income pregnant women attending prenatal nutrition programs between 1990 and 1993. RESULTS: Among low and average BMI women (all race-ethnicity groups), weight gain within Institute of Medicine ranges resulted in significant LBW reductions; further LBW reductions at gains beyond Institute of Medicine ranges were offset by increasing high birth weight risk. Among women of high and obese BMI, LBW trends were less pronounced; thus, the benefit of gaining within the Institute of Medicine range was less apparent. Although blacks in every BMI-weight gain category had lower mean birth weights than white women, gaining in the upper end of the Institute of Medicine ranges did not provide a consistent LBW reduction for black women; adjusted LBW odds ratios and 95% confidence intervals for gains in the upper relative to the lower half of the Institute of Medicine range were 1.3 (0.8, 2.1), 0.7 (0.5, 1.03), 0.3 (0.2, 0.8), and 1.3 (0.7, 2.5) for black women of low, average, high, and obese BMI, respectively. CONCLUSION: Institute of Medicine pregnancy weight gain ranges recommended for low and average BMI women appear reasonable, but recommendations for high and obese BMI women require further evaluation. The recommendation that black women in all BMI groups strive for gains toward the upper ends of the ranges is not supported clearly by these data.

High and low hemoglobin levels during pregnancy: differential risks for preterm birth and small for gestational age.

OBJECTIVE: To examine the association of maternal hemoglobin during pregnancy with preterm birth and small for gestational age (SGA). METHODS: We performed a retrospective cohort analysis of hemoglobin and birth outcome among 173,031 pregnant women who attended publicly funded health programs in ten states and delivered a liveborn infant at 26-42 weeks' gestation. We defined preterm as less than 37 weeks' gestation and SGA as less than the tenth percentile of a US fetal growth reference. RESULTS: Risk of preterm birth was increased in women with low hemoglobin level in the first and second trimester. The odds ratio (OR) for preterm birth with moderate-to-severe anemia during the first trimester (more than three standard deviations [SD] below reference median hemoglobin, equivalent to less than 95 g/L at 12 weeks' gestation) was 1.68 (95% confidence interval [CI] 1.29, 2. 21). Anemia was not associated with SGA. High hemoglobin level during the first and second trimester was associated with SGA but not preterm birth. The ORs for SGA in women with very high hemoglobin level during the first and second trimester (more than three SDs above reference median hemoglobin, equivalent to greater than 149 g/L at 12 weeks' gestation and greater than 144 g/L at 18 weeks') were 1.27 (95% CI 1.02, 1.58) and 1.79 (95% CI 1.49, 2.15), respectively. CONCLUSION: These data highlight the importance of considering anemia and high hemoglobin level as indicators for adverse pregnancy outcome. An elevated hemoglobin level (greater than 144 g/L) is an indicator for possible pregnancy complications associated with poor plasma volume expansion, and should not be mistaken for good iron status.

Medically advised, mother's personal target, and actual weight gain during pregnancy.

OBJECTIVE: To evaluate whether advice on pregnancy weight gain from health care professionals, women's target weight gain (how much weight women thought they should gain), and actual weight gain corresponded with the 1990 Institute of Medicine recommendations. METHODS: Predominantly white, middle-class women participating in a mail panel reported their prepregnancy weights, heights, and advised and target weight gains on a prenatal questionnaire (n = 2237), and their actual weight gains on a neonatal questionnaire (n = 1661). Recommended weight gains were categorized for women with low body mass index (BMI) (less than 19.8 kg/m2) as 25-39 lb; for women with average BMI (19.8-26.0 kg/m2) as 25-34 lb; and for women with high BMI (more than 26.0-29.0 kg/m2) and very high BMI (more than 29.0 kg/m2) as 15-24 lb. RESULTS: Twenty-seven percent of the women reported that they had received no medical advice about pregnancy weight gain. Among those who received advice, 14% (95% confidence interval [CI] 12%, 16%) had been advised to gain less than the recommended range and 22% (95% CI 20%, 24%) had been advised to gain more than recommended. The odds of being advised to gain more than recommended were higher among women with high BMIs and with very high BMIs compared with women with average BMIs. Black women were more likely than white women to report advice to gain less than recommended. Advised and target weight gains were associated strongly with actual weight gain. Receiving no advice was associated with weight gain outside the recommendations. CONCLUSION: Greater efforts are required to improve medical advice about weight gain during pregnancy.

Prepregnancy body mass index and pregnancy weight gain: associations with preterm delivery. The NMIHS Collaborative Study Group.

OBJECTIVE: To examine associations between rate of pregnancy weight gain and preterm delivery among women of varying prepregnancy body mass indices (BMI). METHODS: Subjects were 3511 mother-infant pairs from the 1988 National Maternal and Infant Health Survey. Prenatal weight measured between 14 and 28 weeks' gestation was used to calculate rate of pregnancy weight gain for each woman. Weight gain (lb/week) was categorized as low (under 0.5), average (0.5-1.5), or high (above 1.5). Prepregnancy BMI was calculated as weight divided by height in (kg/m(2)) and categorized as low (under 19.8), average (19.8-26.0), and high (above 26). Delivery before 37 weeks' gestation was considered preterm. Associations between BMI, weight gain, and preterm delivery were examined before and after exclusion of medically indicated preterm deliveries and pregnancies complicated by maternal medical conditions potentially related to weight gain or fetal growth restriction. Associations were expressed as odds ratios (OR) adjusted for several potential confounding factors. RESULTS: Women with low pregnancy weight gain were at increased risk of preterm delivery. The magnitude of risk varied according to a woman's prepregnancy BMI. After all exclusions and adjustments for confounders, ORs, and 95% confidence intervals (CI) for low pregnancy weight gain were 6.7 (1.1, 40.6) for underweight women, 3.6 (1.6, 8.0) for average-weight women, and 1.6 (0.7, 3.5) for overweight women compared with average-weight women with average pregnancy weight gain. CONCLUSIONS: Low weight gain in pregnancy was associated with increased risk of preterm delivery, particularly if women were underweight or of average weight before pregnancy.

Vitamin D status and determinants of deficiency among non-pregnant Jordanian women of reproductive age.

BACKGROUND/OBJECTIVES: Vitamin D deficiency, a risk factor for osteomalacia and osteoporosis, is a re-emerging health problem globally. While sunlight is an important vitamin D source, previous investigations among women whose culture encourages skin covering have been small, not nationally representative, or both. We investigated serum 25-hydroxyvitamin D (25(OH)D(3)) status and factors associated with deficiency in a nationally representative survey of 2013 Jordanian women of reproductive age in Spring 2010. SUBJECTS/METHODS: We measured 25(OH)D(3) concentrations by liquid chromatography-tandem mass spectrometry and calculated prevalence ratios for deficiency associated with skin covering and other factors. RESULTS: Results showed 60.3% (95% CI: 57.1-63.4%) deficiency (<12 ng/ml) and 95.7% (95% CI: 94.4-96.8%) insufficiency (<20 ng/ml) among women. Prevalence of deficiency was 1.60 times higher for women who covered with a scarf/hijab (95% CI: 1.06-2.40, P = 0.024) and 1.87 times higher for women who wore full cover, or a niqab (95% CI: 1.20-2.93, P = 0.006), compared with the women who did not wear a scarf/hijab or niqab. Compared with rural women completing at least secondary education, prevalence of deficiency was 1.30 times higher for urban women of the same education level (95% CI: 1.08-1.57, P = 0.006), 1.18 times higher for urban women completing less than secondary education (95% CI: 0.98-1.43, P = 0.09), and 0.66 times lower for rural women completing less than secondary education (95% CI: 0.52-0.84, P = 0.001). CONCLUSION: Vitamin D deficiency and insufficiency pose significant public health problems in Jordanian women. Prevalence of deficiency is significantly higher among urban women and among women who cover with a scarf/hijab or niqab.

Exposure to environmental tobacco smoke and birth outcome: increased effects on pregnant women aged 30 years or older.

The purposes of this study were to examine the association between self-reported environmental tobacco smoke (ETS) exposure during pregnancy and birth weight, prematurity, and small-for-gestational age infants and to determine whether these associations differ by maternal age. Data from the Pregnancy Nutrition Surveillance System from two states that collected data on both passive and active smoking for the period 1989-1994 were analyzed. ETS exposure was defined as reported exposure to the cigarette smoke of a household member. Multiple logistic and linear regression analyses were used to evaluate the association between ETS and birth outcomes. The mean adjusted birth weight among infants of nonsmoking mothers age 30 years or older was 90 g less among infants exposed to ETS than among infants not exposed. No significant association was found among infants of younger nonsmoking mothers. Similarly, the risks for low birth weight (adjusted odds ratio (OR) = 2.42, 95% confidence interval 1.51-3.87) and preterm delivery (adjusted OR = 1.88, 95% confidence interval 1.22-2.88) were elevated among older nonsmokers exposed to ETS, but not among younger nonsmokers exposed to ETS (adjusted OR = 0.97, 95% confidence interval 0.76-1.23; adjusted OR = 0.92, 95% confidence interval 0.76-1.13, for low birth weight and preterm delivery, respectively). These findings indicate that the association between ETS exposure and adverse pregnancy outcomes appears to be modified by maternal age.

Trends in pregnancy weight gain within and outside ranges recommended by the Institute of Medicine in a WIC population.

OBJECTIVES: To examine the proportion of women with a pregnancy weight gain below, within, and above ranges recommended by the Institute of Medicine from 1990 to 1996. METHODS: Our study population included women attending Special Supplemental Nutrition Program for Women, Infants and Children (WIC) clinics in five states who delivered a liveborn singleton infant at term (N = 120,531). Pregnancy weight gain was self-reported at the postpartum visit. RESULTS: Only 34% of women gained weight within recommended ranges and there was little change in this proportion from 1990 to 1996. The proportion of women gaining less than their recommended weight decreased from 23.4% to 22.0%, and the proportion gaining more than recommended increased from 41.5% to 43.7% during the study period. Stratified analyses revealed similar trends within all race-ethnicity, age, parity, trimester of WIC initiation, and trimester of prenatal care initiation strata and among women in low, average, and high prepregnancy body mass index categories. There was no change in the weight gain distribution among obese women. Absolute and relative increases in the proportion of women gaining more weight than recommended were greatest among women who were underweight, Asian or Native American, less than 20 years of age, multiparous, and who initiated WIC and prenatal care in the third trimester. CONCLUSIONS: Pregnancy weight gain increased among this population of WIC participants from 1990 to 1996.

Maternal weight gain and preterm delivery: differential effects by body mass index.

We examined associations between weight gain (kg) per week of pregnancy and net weight gain per week of pregnancy (weight gain - birth weight/weeks of gestation at delivery) and preterm delivery in a population of 266,172 low-income women. Risk of preterm delivery was lowest among women with intermediate weight gain (0.35 to <0.46 kg/week) and net weight gain (0.27 to <0.37 kg/week). Both lower and higher weight gains and net weight gains per week were associated with an increased risk for preterm delivery. Associations, however, were not uniform across body mass index categories. Compared with women gaining 0.35 to <0.46 kg/week, preterm risk differences (95% confidence limits) for women gaining <0.10 kg/week were +9.5% (+6.5, +12.4) for underweight women, +6.7% (+5.6, +7.9) for average-weight women, +3.5% (+2.0, +4.9) for overweight women, and +0.4% (-0.4, +1.2) for obese women. The opposite pattern was observed with high weight gain. Preterm risk differences for weight gains >0.65 kg/week ranged from +0.8% (-0.7, +2.1) for underweight women, to +2.5% (+1.3, +3.9) for obese women. We also evaluated weight gain per week in the latter part of pregnancy (from week 14 to delivery). The same basic patterns were observed; however, variation in the associations across body mass index groups was not as marked.

Is maternal obesity a risk factor for anencephaly and spina bifida?

To determine whether the risk of having an infant with anencephaly or spina bifida is greater among obese women than among average-weight women, we compared 307 Atlanta-area women who gave birth to a liveborn or stillborn infant with anencephaly or spina bifida (case group) with 2,755 Atlanta-area women who gave birth to an infant without birth defects (control group). The infants of control women were randomly selected from birth certificates and frequency-matched to the case group by race, birth hospital, and birth period from 1968 through 1980. After adjusting for maternal age, education, smoking status, alcohol use, chronic illness, and vitamin use, we found that, compared with average-weight women, obese women (pregravid body mass index greater than 29) had almost twice the risk of having an infant with spina bifida or anencephaly (odds ratio = 1.9; 95% confidence limits = 1.1, 3.4). A woman's risk increased with her body mass index: adjusted odds ratios ranged from 0.6 (95% confidence limits = 0.3, 2.1) for very underweight women to 1.9 for obese women.

What are preschool children eating? A review of dietary assessment.

Accurate assessment of dietary intake among preschool-aged children is important for clinical care and research, for nutrition monitoring and evaluating nutrition interventions, and for epidemiologic research. We identified 25 studies published between January 1976 and August 2000 that evaluated the validity of food recalls (n = 12), food frequency questionnaires (n = 9), food records (n = 2), or other methods (n = 2). We identified four studies that evaluated the reproducibility of food frequency questionnaires. Validity studies varied in validation standard and study design, making comparisons between studies difficult. In general, food frequency questionnaires overestimated total energy intake and were better at ranking, than quantifying, nutrient intake. Compared with the validation standard, food recalls both overestimated and underestimated energy intake. When choosing a method to estimate diet, both purpose of the assessment and practicality of the method must be considered, in addition to the validity and reproducibility reported in the scientific literature.

An outbreak of hypervitaminosis D associated with the overfortification of milk from a home-delivery dairy.

OBJECTIVES: The purpose of the study was to identify cases of hypervitaminosis D caused by the inadvertent overfortification of milk from a home-delivery dairy and to identify risk factors for this illness. METHODS: Hospital discharge, laboratory, and state health department data were used to define, identify, and describe cases of hypervitaminosis D diagnosed in the exposed communities between January 1, 1985, and June 30, 1991. To identify disease risk factors, community-based sex- and age-matched controls were used in a case-control study. RESULTS: Of the 56 case patients identified, at least 41 were hospitalized; 2 died. The study included 33 case patients and 93 control subjects. Nineteen of the 33 case patients had been customers of the implicated dairy. Risk of illness rose with increasing consumption of the dairy's milk and was also associated with vitamin D supplement use, sunburn susceptibility, and cancer history. Accounting for these factors did not alter the association between drinking the dairy's milk and developing hypervitaminosis D. CONCLUSIONS: Overfortification of milk with vitamin D can lead to hypervitaminosis D, manifested by severe illness and death. The episode highlights the need for monitoring the fortification process and enforcing the upper limit for vitamin D addition to milk.

Increasing prevalence of overweight among US low-income preschool children: the Centers for Disease Control and Prevention pediatric nutrition surveillance, 1983 to 1995.

OBJECTIVE: To determine whether the prevalence of overweight in preschool children has increased among the US low-income population. DESIGN: Analysis using weight-for-height percentiles of surveillance data adjusted for age, sex, and race or ethnicity. SETTING: Data from 18 states and the District of Columbia were examined. SUBJECTS: Low-income children <5 years of age who were included in the Centers for Disease Control and Prevention Pediatric Nutrition Surveillance System. RESULTS: The prevalence of overweight increased from 18.6% in 1983 to 21.6% in 1995 based on the 85th percentile cutoff point for weight-for-height, and from 8.5% to 10.2% for the same period based on the 95th percentile cutoff point. Analyses by single age, sex, and race or ethnic group (non-Hispanic white, non-Hispanic black, and Hispanic) all showed increases in the prevalence of overweight, although changes are greatest for older preschool children. CONCLUSION: Overweight is an increasing public health problem among preschool children in the US low-income population. Additional research is needed to explore the cause of the trend observed and to find effective strategies for overweight prevention beginning in the preschool years.

Subclinical health effects in a population exposed to excess vitamin D in milk.

To evaluate subclinical health effects of excess vitamin D, a cross-sectional study was conducted of persons consuming milk from a dairy that had overfortified milk for at least 4 years. Milk consumption, sunlight exposure, medical symptoms, serum 25-hydroxyvitamin D (25[OH]D), serum and urinary calcium, and indicators of renal function were measured. Increased milk consumption was associated with increased serum 25(OH)D and urinary calcium. However, the prevalences of elevated serum 25(OH)D and calcium were no greater than expected, and data indicated normal renal function. It was concluded that most persons exposed to excess vitamin D exhibited no measurable adverse subclinical effects.

Vitamin A and cardiac outflow tract defects.

To assess the relationship between maternal intake of vitamin A and cardiac outflow tract defects, we examined data from a population-based case-control study among liveborn infants born from 1987 through 1989 to mothers residing in the Baltimore-Washington area. Case infants (126) had a nonsyndromic cardiac outflow tract defect. Control infants (679) did not have birth defects and were a stratified random sample of liveborn infants from the same area. The main exposure was average daily maternal intake of retinol and provitamin A carotenoids from foods and supplements during the year before conception. Compared with an average intake of less than 10,000 IU, retinol intake of 10,000 IU or more from supplements was associated with a ninefold increased risk for transposition of the great arteries (odds ratio = 9.2; 95% confidence interval = 4.0-21.2), but not for outflow tract defects with normally related arteries (odds ratio = 0.8; 95% confidence interval = 0.1-6.6). Similar intakes of carotenoids and dietary retinol were not associated with an increased risk for either type of outflow tract defect.

High prevalence of postpartum anemia among low-income women in the United States.

OBJECTIVE: To determine the prevalence of anemia from 4 to 26 weeks post partum and to examine prenatal predictors of postpartum anemia. STUDY DESIGN: Retrospective cohort analysis of 59,428 participants in the Special Supplemental Nutrition Program for Women, Infants, and Children in 12 US states. RESULTS: The prevalence of postpartum anemia was 27%. Anemia rates were higher among minority women, reaching 48% among non-Hispanic black women. Of 9129 women who had normal hemoglobin in the third trimester, 21% had postpartum anemia. Prenatal anemia was the strongest predictor of postpartum anemia (adjusted odds ratio, 2.7; 95% confidence interval, 2.5-2.8). Maternal obesity, multiple birth, and not breast-feeding also predicted postpartum anemia. CONCLUSION: The high prevalence of post partum anemia among low-income women highlights the importance of anemia screening at 4 to 6 weeks post partum. These data suggest that screening should not be limited, as it is at present, to women considered at high risk.

Reporting efficiency during a measles outbreak in New York City, 1991.

OBJECTIVES: During an epidemic of measles among preschool children in New York City, an investigation was conducted in 12 city hospitals to estimate reporting efficiency of measles to the New York City Department of Health. METHODS: Measles cases were identified by review of hospital emergency room and infection control logs and health department surveillance records. The Chandra Sekar Deming method was used (1) to estimate the total number of measles cases in persons less than 19 years old who presented to the 12 hospitals from January through March 1991 and (2) to estimate reporting efficiency. Information on mechanisms for reporting measles cases was collected from hospital infection control coordinators. RESULTS: The Chandra Sekar Deming method estimated that 1487 persons with measles presented to the 12 hospitals during the study period. The overall reporting efficiency was 45% (range = 19% to 83%). All 12 hospitals had passive surveillance for measles; 2 also had an active component. These 2 hospitals had the first and third highest measles reporting efficiencies. CONCLUSIONS: The reporting efficiency of measles cases by New York City hospitals to the health department was low, indicating that the magnitude of the outbreak was substantially greater than suggested by the number of reported cases.

Preconceptional folate intake and malformations of the cardiac outflow tract. Baltimore-Washington Infant Study Group.

We compared cases with outflow tract defects (N = 126) with controls representative of the same birth cohort (N = 679). Infants with clinically recognized syndromes were excluded. Daily total maternal folate intake of > or =245 microg was inversely related to risk of cardiac outflow tract defects among those with transposition (odds ratio estimates: 0.65, 0.78, and 0.76 with increasing quartile of daily folate intake), but positively related among those with normally related vessels (corresponding odds ratio estimates: 1.18, 1.59, and 1.68). This difference disappeared when maternal intake of supplemental folic acid of > or =400 microg compared with <400 microg was considered, excluding dietary intake [odds ratio (OR) = 1.04; 95% confidence interval (CI) = 0.5-2.2 for infants with transposition, and OR = 0.91; 95% CI = 0.5-1.8 for those without transposition of the great arteries].

Elevated midtrimester serum methylmalonic acid levels as a risk factor for neural tube defects.

The role of folic acid in the primary prevention of neural tube defects (NTDs) is well established. However, questions related to the protective mechanism remain unanswered. To help answer these questions, we designed a case-control study to assess the role of folate- and cobalamin-related metabolites in the pathogenesis of NTDs. Concentrations of folate, cobalamin, and 14 other related metabolites were measured by gas chromatography/mass spectrometry in midtrimester serum specimens from 32 women with an NTD-affected pregnancy and from 132 control women, and in serum specimens from 46 nonpregnant women who had a history of NTD-affected pregnancy and from 43 nonpregnant control women. Log-transformed means of metabolites were compared between case and control women for both the midtrimester and nonpregnant groups. In the pregnant group, serum methylmalonic acid (MMA) concentrations were higher among case women than among control women (130 vs 105 nM). There was a strong dose-response relationship between midtrimester serum MMA level and the risk for an NTD-affected pregnancy, with the relative risk increasing 13-fold for women with MMA levels > 90th percentile. In the nonpregnant group, there was no difference in serum MMA levels between case and control women (140 vs 140 nM). Thus, the serum MMA levels of women in the midtrimester of pregnancies unaffected by NTDs were significantly lower than the levels of nonpregnant women, whereas the levels of women whose pregnancies were affected by NTDs were similar to those of nonpregnant women. The finding of elevated MMA serum concentrations among women in the midtrimester of NTD-affected pregnancies suggests that cobalamin may be involved in the etiology of NTDs. The possible role of cobalamin in relation to the protective effect of folic acid needs further evaluation.