Maternal vitamin D status: implications for the development of infantile nutritional rickets

The Assessment of Vitamin D Levels in Pregnant Women is not Associated to Fetal Growth Restriction: A Cross Sectional Study

OBJECTIVE

 To assess maternal serum levels of vitamin D in fetuses appropriate for gestational age (AGA), small for gestational age (SGA), and with fetal growth restriction (FGR) according to estimated fetal weight (EFW).

METHODS

 This cross-sectional study included 87 pregnant women between 26 and 36 weeks of gestation: 38 in the AGA group, 24 in the SGA group, and 25 in the FGR group. Maternal serum vitamin D levels were assessed using the chemiluminescence method. The Fisher exact test was used to compare the results between the groups.

RESULTS

 The mean ± standard deviation (SD) of maternal age (years) and body mass index (kg/m²) in the AGA, SGA, and FGR groups were 25.26 ± 8.40 / 26.57 ± 4.37; 25.04 ± 8.44 / 26.09 ± 3.94; and 25.48 ± 7.52 / 26.24 ± 4.66, respectively (p > 0.05). The maternal serum vitamin D levels (mean ± SD) of the AGA, SGA, and FGR groups were 22.47 ± 8.35 ng/mL, 24.80 ± 10.76 ng/mL, and 23.61 ± 9.98 ng/mL, respectively, but without significant differences between the groups (p = 0.672).

CONCLUSION

 Maternal serum vitamin D levels did not present significant differences among pregnant women with AGA, SGA, or FGR fetuses between 26 and 36 weeks of gestation according to EFW.

A joint medico-historical and paleopathological perspective on vitamin D deficiency prevalence in post-Medieval Netherlands

OBJECTIVE

By applying a joint medico-historical and paleopathological perspective, this paper aims to improve our understanding of factors influencing past vitamin D deficiency in ten Dutch 17th to 19th-century communities of varying socioeconomic status and settlement type.

MATERIALS

Vitamin D deficiency is evaluated in 733 individuals of both sexes and all age groups: Silvolde (n = 16), Rotterdam (n = 23), Rhenen (n = 24), Noordwijkerhout (n = 27), Gouda1and 2 (n = 40; n = 59), Roosendaal (n = 51), Den Haag (n = 93), Hattem (n = 113), and Beemster (n = 287).

METHODS

Rickets and residual rickets are macroscopically assessed using established criteria. Hypotheses formulated based on medico-historical texts are investigated via multivariate statistical analysis of vitamin D deficiency prevalence.

RESULTS

Vitamin D deficiency prevalence ranges from 13.7 % (7/51) in Roosendaal to 48.1 % (13/27) in Noordwijkerhout, with an onset of < 4 years, and higher rates in cities, conforming to medico-historical texts. Patterns of child labor are likely key. In contrast, socioeconomic status did not statistically significantly influence vitamin D deficiency prevalence rates.

CONCLUSION

Systematically collected paleopathological data enabled evaluation of medico-historical texts and provided insights into the role that socioeconomic status and settlement type played on the prevalence of vitamin D deficiency.

SIGNIFICANCE

Combining medico-historical texts and large-scale paleopathological data enables disease patterning to be embedded in a comprehensive biocultural perspective.

LIMITATIONS

Comparisons may be limited by the small sample size of high socioeconomic status nonadults and some of the collections.

SUGGESTIONS FOR FUTURE RESEARCH

Analysis of more individuals and sites would improve our understanding of disease patterns.

Umbilical cord N-terminal procollagen of type l collagen (P1NP) and beta C-terminal telopeptide (βCTX) levels in term pregnancies with vitamin D deficiency

AIMS

The aim of the present study was to evaluate umbilical cord N-terminal procollagen of type l collagen (P1NP) and beta C-terminal telopeptide (βCTX) levels in term pregnancies with vitamin D deficiency.

MATERIALS AND METHODS

Ninety-two pregnant women between 19 and 35-years-old who delivered at term gestational age were included in the study and divided into deficient (n = 32), insufficient (n = 30), and normal (control) vitamin D levels (n = 30).

RESULTS

Maternal demographic characteristics and biochemical parameters were similar among groups. The mean umbilical cord P1NP level was 221.4 (211.7-231.0, 95%CI) pg/mL in the vitamin D deficiency group, 282.5 (271.2-293.8, 95%CI) pg/mL in the vitamin D insufficiency group, and 280.9 (270.9-290.8, 95%CI) pg/mL in the control group and significantly lower in vitamin D deficiency group than others (p < .001). Umbilical cord P1NP level was similar in the vitamin D insufficiency group and control group (p = .971). The mean umbilical cord βCTX level was 5530, 9 (5511.5-5550.3, 95%CI) pg/mL in the vitamin D deficiency group, 5516.3 (5498.4-5534.2, 95%CI) pg/mL in the vitamin D insufficiency group, and 5510 (5491.4-5528.5, 95%CI) pg/mL in the control group, which was statistically similar among the groups (p = .251).

CONCLUSION

Our results indicated that vitamin D deficiency during pregnancy affects fetal bone osteoblast activity.

The effect of vitamin D administration on vitamin D status and respiratory morbidity in late premature infants

OBJECTIVE

To assess whether increment of vitamin D daily intake results in improved serum25(OH) vitamin D levels and reduced respiratory morbidity in premature infants.

METHODS

A randomized double-blind clinical pilot trial, including preterm infants born at 32 + 6 to 36 + 6 weeks of gestation. The control group received 400 international units (IU) of cholecalciferol daily compared to 800 IU daily in the intervention group. Levels of 25(OH) vitamin D were measured at birth and 6 and 12 months of age. Respiratory morbidity was followed until 1 year of age.

RESULTS

Fifty subjects were recruited during the study period; the median measured 25(OH) vitamin D levels in the control vs intervention groups were: 26.5 vs 34 nmol/L (P = .271) at birth, 99 vs 75.5 nmol/L (P = .008) at 6 months and 72.5 vs 75 nmol/L (P = .95) at 12 months of age. Infants with insufficient vitamin D (<75 nmol/L) levels had higher respiratory morbidity. Serum vitamin 25(OH) D is a fair predictor for respiratory symptoms (area under the curve [AUC], 0.697; 95% confidence interval [CI], 0.509-0.885; P = .047) and for recorded acute respiratory illnesses (AUC, 0.745; 95% CI, 0.569-0.922; P = .012).

CONCLUSION

Doubling the daily intake of vitamin D in premature infants did not increase serum 25(OH) vitamin D level, due to poor compliance in the intervention group. We found an inverse association between serum 25(OH) vitamin D and respiratory symptoms, indicating vitamin D deficiency is a fair predictor for respiratory morbidity.

An Overview of Rickets in Children

Rickets is a common bone disease worldwide that is associated with disturbances in calcium and phosphate homeostasis and can lead to short stature and joint deformities. Rickets can be diagnosed based on history and physical examination, radiological features, and biochemical tests. It can be classified into 2 major groups based on phosphate or calcium levels: phosphopenic and calcipenic. Knowledge of categorization of the type of rickets is essential for prompt diagnosis and proper management. Nutritional rickets is a preventable disease through adequate intake of vitamin D through both dietary and sunlight exposure. There are other subtypes of rickets, such as vitamin D-dependent type 1 rickets and vitamin D-dependent type 2 rickets (due to defects in vitamin D metabolism), renal rickets (due to poor kidney function), and hypophosphatemic rickets (vitamin D-resistant rickets secondary to renal phosphate wasting wherein fibroblast growth factor-23 (FGF-23) often plays a major role), which requires closer monitoring and supplementation with activated vitamin D with or without phosphate supplements. An important development has been the introduction of burosumab, a human monoclonal antibody to FGF-23, which is approved for the treatment of X-linked hypophosphatemia among children 1 year and older.

Micro-CT assessment of dental mineralization defects indicative of vitamin D deficiency in two 17th-19th century Dutch communities

OBJECTIVES

This study investigates vitamin D deficiency patterns in individuals from birth to the beginning of adolescence. Microscopic computed tomography (micro-CT) evaluation of interglobular dentine (IGD) in teeth provides information on the age of disease onset and the number of deficient periods per individual, which will increase our understanding of factors influencing vitamin D deficiency prevalence, including sociocultural practices and latitude.

MATERIALS AND METHODS

Beemster and Hattem, two Dutch 17th-19th century communities, yielded relatively high prevalences of rickets (15-24%) and residual rickets (15-24%). From the affected individuals, a subsample of 20 teeth were selected for micro-CT scanning. Thin sections were made of 17 teeth, consisting of 6 teeth with and 11 teeth without observable IGD on micro-CT that were included for method comparison.

RESULTS

About 19 out of 29 (65.5%) individuals (one tooth was deemed unobservable) presented with IGD on micro-CT. Eight of the 11 (72.7%) individuals without IGD on micro-CT demonstrated histologically visible IGD. In 40.7% (11/27) of the affected individuals (combined micro-CT and histology results), vitamin D deficiency was recurrent, and in four individuals, some episodes occurred at approximately annual intervals suggesting vitamin D deficiency was seasonal. In three individuals, IGD occurred in the dentine formed around birth, suggesting maternal vitamin D deficiency.

DISCUSSION

Micro-CT analysis of IGD is found to be a valuable non-destructive method that can improve our understanding of the influence of sociocultural practices and latitude on disease development within age and sex groups in past communities.

Maternal and neonatal vitamin D deficiency and transient tachypnea of the newborn in full term neonates

AIM

To investigate the association between maternal and neonatal serum 25-hydroxyvitamin D (25-OHD) levels and development of transient tachypnea of the newborn (TTN) in full term infants.

METHODS

This was a prospective case-control study carried out on 30 neonates with TTN and their mothers and 30 control neonates and their mothers. Levels of 25-OHD were measured in maternal and neonatal blood samples that were obtained in the first 12-24 h of postnatal age.

RESULTS

Both maternal and neonatal 25-OHD levels in the TTN group were significantly lower compared to the control group (P=0.0001). A negative correlation was observed between neonatal 25-OHD level and average hospital stay (P=0.0001).

CONCLUSION

We observed that lower maternal and neonatal vitamin 25-OHD levels were associated with TTN development in full term infants.

Dose-Response Effects of Early Vitamin D Supplementation on Neurodevelopmental and Respiratory Outcomes of Extremely Preterm Infants at 2 Years of Age: A Randomized Trial

BACKGROUND

Many extremely preterm infants have low vitamin D concentrations at birth, but early childhood outcomes after vitamin D supplementation have not been reported.

OBJECTIVE

To determine a dose-response relationship between increasing doses of enteral vitamin D in the first 28 days after birth and cognitive scores at 2 years of age.

METHODS

In this phase II double-blind dose-response randomized trial, infants with gestational ages between 23 and 27 weeks were randomly assigned to receive placebo or a vitamin D dose of 200 or 800 IU/day from day 1 of enteral feeding to postnatal day 28. The primary outcome of this follow-up study was Bayley III cognitive score at 22-26 months of age.

RESULTS

Seventy of 80 survivors had a follow-up evaluation at 2 years of age (88%). There were no significant differences in cognitive scores between supplementation groups (p = 0.47). Cognitive scores did not differ between the higher vitamin D dose group and the placebo group (median difference favoring the 800 IU group: +5 points; 95% CI: -5 to 15; p = 0.23). The linear trend between increasing doses of vitamin D and reduction of neurodevelopmental impairment (placebo group: 54%; 200 IU group: 43%; 800 IU group: 30%; p = 0.08) or language impairment (placebo group: 64%; 200 IU group: 57%; 800 IU group: 45%; p = 0.15) was not statistically significant. Respiratory outcomes at 2 years of age (need for supplemental oxygen or asthma medications) did not differ between groups.

CONCLUSION

In extremely preterm infants, early vitamin D supplementation did not significantly improve cognitive scores. Though underpowered for clinically meaningful differences in early childhood outcomes, this trial may help determine dosing for further investigation of vitamin D supplementation.

Effect of different doses of vitamin D supplementation on preterm infants - an updated meta-analysis

OBJECTIVE

Vitamin D deficiency (VDD) is common among infants, especially in preterm babies. There are some controversies over its use on body development, immune function and incidence of bronchopulmonary dysplasia (BPD).

METHODS

We systematically reviewed PubMed, Embase, and Cochrane databases for studies in English, and in Wanfang, VIP, and Cnki databases for Chinese studies (databases were last launched on 1 August 2016).

RESULTS

Twelve original random controlled studies (seven in English and five in Chinese) were included (1). There are no differences between high-dose (800-1000 IU/d) and low-dose (400 IU/d) groups on calcium, phosphorus, and 25(OH)D concentrations (p > .05). However, length gain and head circumference gain are significantly increased in the high-dose group (p < .05) (2). IL-2, Ig-A, and Ig-G levels are significant increased in the vitamin D supplementation group compared with the control group (p < .05) (3). With respect to BPD, there is no significant difference between the vitamin D supplementation group and the control group (p > .05).

CONCLUSIONS

In preterm infants, daily supplementation of vitamin D in doses of 800-1000 IU compared with 400 IU appears to be better not only in development but also in immune function. But clinical trials with a larger sample size are still needed.

Vitamin D levels in newborns and association with neonatal hypocalcemia

OBJECTIVE

Vitamin D has many important functions in our body. Especially in intrauterine and early infancy periods, Vitamin D plays a major role in bone development, growth, and the maturation of tissues such as lung and brain. Fetus is dependent on the mother in terms of Vitamin D and maternal Vitamin D deficiency results in a Vitamin D deficient newborn. The purpose of this study was to determine the levels of Vitamin D in newborns and to investigate the association between Vitamin D status of the baby and neonatal hypocalcemia.

METHOD

Vitamin D, calcium, and parathyroid hormone levels of 750 infants, born between 1 January 2014 and 30 June 2015 and followed in Ondokuz Mayıs University Neonatal Intensive Care Unit were analyzed retrospectively. Blood levels of Vitamin D were checked within 3 days after birth. A 25(OH)D3 level of <10 ng/ml indicated severe, levels between 10 and 20 ng/ml, which indicated moderate and levels between 20 and 30 ng/ml indicated mild Vitamin D deficiency. Serum calcium levels below 8 mg/dl in term infants and below 7 mg/dl in preterm infants were accepted as hypocalcemia. Hypocalcemia that developed within the first week after birth was defined as early, while hypocalcemia after one week were defined as late hypocalcemia.

RESULTS

A total of 44% of the infants in the study were girls, while 56% were boys; 38% were term and 62% were preterm. Average 25(OH)D3 level of all infants was 11.4 ± 10.2 (0-153) ng/ml. Only 30 (4%) infants had normal (>30 ng/ml) 25(OH)D3 levels; 68 (9%) had mild, 234 (31%) had moderate and 418 (56%) had severe vitamin D deficiency. No correlation was found between Vitamin D levels and gender, mother's age, gestational week or birth weight. In 79 (17.2%) preterms, neonatal hypocalcemia was observed. Vitamin D levels of the premature infants who had early neonatal hypocalcemia were statistically significantly lower when compared with those who did not have early neonatal hypocalcemia (p = .02). No significant difference was found between the Vitamin D levels of the term infants who had early neonatal hypocalcemia and those who did not (p= .29). No significant difference was found between the Vitamin D levels of the infants who had late neonatal hypocalcemia and those who did not (in preterm p = .27; in term p = .29).

CONCLUSIONS

Although lack of Vitamin D is preventable and curable, it is an important health problem for newborns in Turkey. In our study, 56% of the infants were found to have severe lack of Vitamin D and lack of Vitamin D was found to be associated with early neonatal hypocalcemia in preterm newborns. However, long-term effects of lack of Vitamin D in infancy are not fully known. In order to be able to prevent neonatal Vitamin D deficiency, 1200 IU/day vitamin D was supplemented to mothers from the 12th gestational week to 6th month of the birth, which was put into effect by the Ministry of Health in 2011, and should be applied by all health workers.

Nutritional rickets around the world: an update

Worldwide, nutritional rickets continues to be an evolving problem with several causes. This paper provides an updated literature review characterising the prevalence, aetiology, pathophysiology and treatment of nutritional rickets worldwide. A systematic review of articles on nutritional rickets from various geographical regions was undertaken. For each region, key information was extracted, including prevalence, cause of rickets specific to the region, methods of confirming the diagnosis and current treatment and preventive measures. Calcium deficiency continues to be a major cause of rickets in Africa and Asia. Vitamin D deficiency rickets is perhaps increasing in the Americas, Europe and parts of the Middle East. There continues to be a distinct presentation of calcium-predominant versus vitamin D predominant rickets, although there are overlapping features. More careful diagnosis of rickets and reporting of 25-OHD concentrations has improved accurate knowledge of rickets prevalence and better delineated the cause. Nutritional rickets continues to be an evolving and multi-factorial problem worldwide. It is on a spectrum, ranging from isolated vitamin D deficiency to isolated calcium deficiency. Specific areas which require emphasis include a consistent community approach to screening and diagnosis, vitamin D supplementation of infants and at-risk children, prevention of maternal vitamin D deficiency and the provision of calcium in areas with low calcium diets.

PILL Series. Vitamin D deficiency

Vitamin D deficiency is common and may contribute to osteopenia, osteoporosis and falls risk in the elderly. Screening for vitamin D deficiency is important in high-risk patients, especially for patients who suffered minimal trauma fractures. Vitamin D deficiency should be treated according to the severity of the deficiency. In high-risk adults, follow-up serum 25-hydroxyvitamin D concentration should be measured 3-4 months after initiating maintenance therapy to confirm that the target level has been achieved. All patients should maintain a calcium intake of at least 1,000 mg for women aged ≤ 50 years and men ≤ 70 years, and 1,300 mg for women > 50 years and men > 70 years.

Attitudes of Pediatricians Regarding Prevention and Treatment of Vitamin D Deficiency

To determine the adherence of pediatricians to the nationwide 'Vitamin D Prophylaxis Program' and to evaluate their attitudes about vitamin D intake. The study was conducted using the Turkish National Pediatrics Association network. The pediatricians were asked to respond to an online questionnaire that included five questions on 'What dose of vitamin D they recommend for supplementation?', 'At what age they start vitamin D supplementation?', 'Supplementation method', 'Clichés and truths about vitamin D', and 'High-dose vitamin D therapy indications'. Responses of 167 pediatricians were evaluated in this study. 75.5% of pediatricians indicated that they recommended vitamin D supplementation in a daily dose of 400 IU. 47.1% started vitamin D supplementation by the end of the 2nd week. 7.83% of pediatricians suggested doubling the daily dose of vitamin D supplementation in infants with delayed tooth eruption, 19.9% suggested immediate cessation of vitamin D supplementation in infants with small anterior fontanels. This study showed that the majority of the pediatricians still prescribe vitamin D prophylaxis late, recommend high doses of vitamin D in cases of delayed tooth eruption, and think that low serum 25-hydroxy vitamin D level regardless of alkaline or phosphatase parathyroid hormone measurement is an indication for high-dose vitamin D (stoss) therapy. These results suggest a need for new training programs focusing on vitamin D supplementation.

Maternal micronutrient consumption periconceptionally and during pregnancy: a prospective cohort study

OBJECTIVE

To examine overall micronutrient intake periconceptionally and throughout pregnancy in a population-based cohort of Australian women.

DESIGN

In a prospective cohort study, micronutrient dosages were extracted from self-reported maternal supplement use, recorded pre-conception, and for each trimester of pregnancy. A food frequency scale (DQESv2) captured usual maternal diet for gestational weeks 14-26. The influence of sociodemographic and lifestyle factors associated with supplement use was examined using logistic regression, and changes in micronutrient intakes prior to and throughout pregnancy were assessed using repeated-measures ANOVA analyses.

SETTING

Metropolitan hospital sites in Melbourne, Australia.

SUBJECTS

Women with a viable singleton pregnancy were recruited at less than 19 weeks' gestation (n 2146).

RESULTS

Compared with non-users, women using supplements during pregnancy were more likely to have planned their pregnancy, be >25 years old, primiparous, Caucasian, non-smokers, have a tertiary education and be consuming a folate-rich diet. Intakes of folate, Fe and Zn were significantly lower in the periconceptional period, compared with other periods (P<0·001). Intakes below Recommended Daily Intake levels were common both periconceptionally and throughout pregnancy, with 19-46 % of women not meeting the Recommended Daily Intake for folate, 68-82 % for Fe and 17-36 % for Zn. Conversely, 15-19 % of women consumed beyond the recommended Upper Limit for folate and 11-24 % for Fe.

CONCLUSIONS

The study highlights the need for improved public health education on nutritional needs during pregnancy, especially among women with lower educational achievements and income.

Formula fed twin infants with recurrent hypocalcemic seizures with vitamin D deficient rickets and hyperphosphatemia

Vitamin D deficient rickets is generally known to occur in breast fed infants. And excessive phosphate ingestion is a main cause of late onset hypocalcemia in formula fed infants. Here we introduce 45-day-old formula fed hypocalcemic twins with recurrent seizure attacks. They were diagnosed as having both of vitamin D deficient rickets and hyperphosphatemia. Radiologic findings indicated mild rickets and the twins were treated with calcium and alfacalcidol. After 3-5 months of oral supplementation, medication was discontinued in both twins. They showed normal growth and calcium, phosphorus, and vitamin D levels during the 6-month follow-up period. Twins can be at risk for hypocalcemia because of their high risk of vitamin D deficiency, low birth weight, and premature birth. Therefore twin pregnant women need ingestion of sufficient vitamin D and calcium.

Association of vitamin D deficiency with acute lower respiratory tract infections in newborns

OBJECTIVE

To determine the association between serum 25-hydroxy vitamin D [25(OH)D] levels and acute respiratory tract infections (ALRTI) in newborns.

STUDY DESIGN

The study group consisted of 30 term newborns with ALRTI who were admitted to our neonatal intensive care unit. Controls were 30 healthy newborns with the same age as the study group. Newborns and their mothers were tested for serum 25(OH)D levels, with a low level defined as ≤15 ng/mL.

RESULTS

The groups were similar in gestational week, birthweight, postnatal age and gender. Forty-three of the 60 infants (including study and control) had low 25(OH)D levels. The median 25(OH)D levels were lower [9.5 ng/mL (IQR = 7.9-12.2)] in the study group than those of the control group [15.5 ng/mL (IQR: 12-18)] (p = 0.0001). The median serum 25(OH)D levels in the mothers of the study group were also lower than those in the mothers of the control group [11.6 ng/mL (IQR = 9.4-15.8) and 17.3 ng/mL (IQR = 13.7-20.6), respectively] (p = 0.0001).

CONCLUSION

Lower blood 25(OH)D levels might be associated with increased risk of ALRTI in term newborn babies. Appropriate vitamin D supplementation during pregnancy and early childhood may enhance newborns' respiratory health.

Evaluation of vitamin D supplementation doses during pregnancy in a population at high risk for deficiency

AIM/BACKGROUND

Vitamin D supplementation during pregnancy is a well-accepted recommendation worldwide; however, the debate about the correct dose is ongoing. We aimed to compare daily doses of 600, 1,200, and 2,000 IU in this randomized, controlled study.

METHODS

The study group consisted of 91 pregnant women aged 16-42 years admitted to Kocaeli Maternity and Children Hospital between April 2011 and April 2012. The participants were randomly divided into 3 groups. 600, 1,200, and 2,000 IU/day of vitamin D was supplemented to group 1 (control group, n = 31), group 2 (n = 31), and group 3 (n = 32), respectively. Serum calcium, 25-hydroxyvitamin D (25OHD), and the calcium/creatinine ratio in spot urine samples were measured in the follow-up period. The serum calcium and 25OHD levels of the mothers' infants were measured as well.

RESULTS

The frequency of vitamin D sufficiency after supplementation was 80% in group 3 and it was significantly higher than in groups 1 (42%) and 2 (39%) (p = 0.03). The frequency of vitamin D sufficiency in the infants of the participants was 91% in group 3 and it was significantly higher than in groups 1 (36%) and 2 (52%) (p = 0.006).

CONCLUSIONS

At least 2,000 IU/day of vitamin D is needed to ensure adequate vitamin D status in pregnancy and early infancy.

Associations between 25-hydroxyvitamin D levels and pregnancy outcomes: a prospective observational study in southern China

BACKGROUND/OBJECTIVES

Observational studies relating 25-hydroxyvitamin D (25(OH)D) and pregnancy outcomes have reported conflicting results. The aim was to assess maternal 25(OH)D status and its association with pregnancy outcomes. A prospective observational study was carried out in Guangzhou city (23 ºN), China.

SUBJECTS/METHODS

Pregnant women (n=2960) and healthy controls (n=100) were recruited at a teaching hospital. Maternal 25(OH)D levels were measured at 16-20-week gestation. The pregnant women, if met inclusion and exclusion criteria, were enrolled in further analysis for pregnancy outcomes (n=1953).

RESULTS

Mean serum 25(OH)D in pregnant women was 27.03±7.92 ng/ml. In total, 18.9 and 48.6% of pregnant women had low (25(OH)D less than or equal to 20 ng/ml) and medium level (25(OH)D 21-29 ng/ml) of vitamin D, respectively. 25(OH)D was highest in summer and lowest in winter, which showed a positive correlation with temperature (R=0.942) and calcium (R=0.074). Most maternal outcomes (premature rupture of membranes break, polyhydramnios, oligohydramnios, pre-eclampsia, cesarean section), fetal outcomes (spontaneous abortions, medically induced labor, fetal death, fetal distress, fetal growth restriction) and neonatal outcomes (malformations, birth weight and height, low birth weight, macrosomia, small-for-gestational age, score of Apgar 1',5', asphyxia of newborn) were not significantly different between groups, but prevalence of gestational diabetes (adjusted odds ratio (OR) 1.017; 95% confidence interval (CI) 1.002-1.033) and preterm delivery (adjusted OR 1.038; 95% CI 1.018-1.059) in high level group (25(OH)D ⩾30 ng/ml) was higher than that in low and medium level groups.

CONCLUSIONS

The prevalence of low level of vitamin D (serum 25OHD ⩽20 ng/ml) was 18.9% among pregnant women in southern China. There were no significant differences in most adverse pregnancy outcomes among pregnant women with different levels of vitamin D at 16-20-week gestation except for higher prevalence of gestational diabetes and preterm delivery in women with high level of vitamin D, possibly related to the older age and higher body mass index of this group.

Trial of daily vitamin D supplementation in preterm infants

OBJECTIVE

To compare the effect of 800 vs 400 IU of daily oral vitamin D3 on the prevalence of vitamin D deficiency (VDD) at 40 weeks' postmenstrual age (PMA) in preterm infants of 28 to 34 weeks' gestation.

METHODS

In this randomized double-blind trial, we allocated eligible infants to receive either 800 or 400 IU of vitamin D3 per day (n = 48 in both groups). Primary outcome was VDD (serum 25-hydroxyvitamin D levels <20 ng/mL) at 40 weeks' PMA. Secondary outcomes were VDD, bone mineral content, and bone mineral density at 3 months' corrected age (CA).

RESULTS

Prevalence of VDD in the 800-IU group was significantly lower than in the 400-IU group at 40 weeks (38.1% vs. 66.7%; relative risk: 0.57; 95% confidence interval: 0.37-0.88) and at 3 months' CA (12.5% vs. 35%; relative risk: 0.36; 95% confidence interval: 0.14-0.90). One infant (2.4%) in the 800-IU group had vitamin D excess (100-150 ng/mL). Bone mineral content (mean ± SD: 79.6 ± 16.8 vs. 84.7 ± 20.7 g; P = .27) and bone mineral density (0.152 ± 0.019 vs. 0.158 ± 0.021 g/cm2; P = .26) were not different between the 2 groups.

CONCLUSIONS

Daily supplementation with 800 IU of vitamin D reduces the prevalence of VDD at 40 weeks' PMA and at 3 months' CA in preterm infants without showing any improvement in bone mineralization. However, there is a possibility that this dose may occasionally result in vitamin D excess.

Maternal vitamin D supplementation to improve the vitamin D status of breast-fed infants: a randomized controlled trial

OBJECTIVE

To determine whether a single monthly supplement is as effective as a daily maternal supplement in increasing breast milk vitamin D to achieve vitamin D sufficiency in their infants.

PATIENTS AND METHODS

Forty mothers with exclusively breast-fed infants were randomized to receive oral cholecalciferol (vitamin D3) 5000 IU/d for 28 days or 150,000 IU once. Maternal serum, breast milk, and urine were collected on days 0, 1, 3, 7, 14, and 28; infant serum was obtained on days 0 and 28. Enrollment occurred between January 7, 2011, and July 29, 2011.

RESULTS

In mothers given daily cholecalciferol, concentrations of serum and breast milk cholecalciferol attained steady levels of 18 and 8 ng/mL, respectively, from day 3 through 28. In mothers given the single dose, serum and breast milk cholecalciferol peaked at 160 and 40 ng/mL, respectively, at day 1 before rapidly declining. Maternal milk and serum cholecalciferol concentrations were related (r=0.87). Infant mean serum 25-hydroxyvitamin D concentration increased from 17±13 to 39±6 ng/mL in the single-dose group and from 16±12 to 39±12 ng/mL in the daily-dose group (P=.88). All infants achieved serum 25-hydroxyvitamin D concentrations of more than 20 ng/mL.

CONCLUSION

Either single-dose or daily-dose cholecalciferol supplementation of mothers provided breast milk concentrations that result in vitamin D sufficiency in breast-fed infants.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov NCT01240265.

Cord serum 25-hydroxyvitamin D and risk of early childhood transient wheezing and atopic dermatitis

BACKGROUND

There is increasing evidence of the effect of maternal vitamin D intake during pregnancy on the risk of asthma and allergic outcomes in offspring. However, studies on the relationship between cord levels of 25-hydroxyvitamin D (25[OH]D) and asthma and allergic diseases are very few.

OBJECTIVE

Our aim was to investigate the associations between cord serum 25(OH)D levels and asthma, wheezing, allergic rhinitis, and atopic dermatitis in the offspring from birth to 5 years.

METHODS

Cord blood samples were collected at birth and analyzed for 25(OH)D levels in 239 newborns from the Etude des Déterminants pré et post natals du développement et de la santé de l'Enfant (EDEN) birth cohort. The children were followed up until age 5 years by using International Study of Asthma and Allergies in Childhood-based symptom questionnaires.

RESULTS

The median cord serum level of 25(OH)D was 17.8 ng/mL (interquartile range, 15.1 ng/mL). By using multivariable-adjusted logistic regression models, a significant inverse association was observed between cord serum 25(OH)D levels and risk of transient early wheezing and early- and late-onset atopic dermatitis, as well as atopic dermatitis, by the ages of 1, 2, 3, and 5 years. We found no association between cord serum 25(OH)D levels and asthma and allergic rhinitis at age 5 years.

CONCLUSIONS

Cord serum 25(OH)D levels were inversely associated with the risk of transient early wheezing and atopic dermatitis by the age of 5 years, but no association was found with asthma and allergic rhinitis.

Hypovitaminosis D and severe hypocalcaemia: the rebirth of an old disease

Vitamin D deficiency, once thought to be eradicated, is becoming a frequent occurence in children, caused mainly by dietary insufficiency. The classical manifestation is rickets, but in infants severe hypocalcaemia may present as stridor, tetany, seizures or, rarely, heart disease. Here, we describe four infants who presented with complications of severe hypocalcaemia secondary to nutritional vitamin D deficiency. (1) Female, 4 months old, several spasms. (2) Male, 8 days old, generalised tonic-clonic seizure. (3) Male, 9 months old, tetany. (4) Male, 4 months old, cardiogenic shock. The cases highlight the importance of child vitamin D supplementation from birth and throughout childhood. We also note that the vitamin D state should be evaluated by the 25(OH)-D value and not the 1,25(OH)2-D.

Vitamin D deficiency in UK South Asian Women of childbearing age: a comparative longitudinal investigation with UK Caucasian women

SUMMARY

This is the first 1-year longitudinal study which assesses vitamin D deficiency in young UK-dwelling South Asian women. The findings are that vitamin D deficiency is extremely common in this group of women and that it persists all year around, representing a significant public health concern.

INTRODUCTION

There is a lack of longitudinal data assessing seasonal variation in vitamin D status in young South Asian women living in northern latitudes. Studies of postmenopausal South Asian women suggest a lack of seasonal change in 25-hydroxy vitamin D [25(OH)D], although it is unclear whether this is prevalent among premenopausal South Asians. We aimed to evaluate, longitudinally, seasonal changes in 25(OH)D and prevalence of vitamin D deficiency in young UK-dwelling South Asian women as compared with Caucasians. We also aimed to establish the relative contributions of dietary vitamin D and sun exposure in explaining serum 25(OH)D.

METHODS

This is a 1-year prospective cohort study assessing South Asian (n = 35) and Caucasian (n = 105) premenopausal women living in Surrey, UK (51° N), aged 20-55 years. The main outcome measured was serum 25(OH)D concentration. Secondary outcomes were serum parathyroid hormone, self-reported dietary vitamin D intake and UVB exposure by personal dosimetry.

RESULTS

Serum 25(OH)D <25 nmol/L was highly prevalent in South Asians in the winter (81 %) and autumn (79.2 %). Deficient status (below 50 nmol/L) was common in Caucasian women. Multi-level modelling suggested that, in comparison to sun exposure (1.59, 95 %CI = 0.83-2.35), dietary intake of vitamin D had no impact on 25(OH)D levels (-0.08, 95 %CI = -1.39 to 1.23).

CONCLUSIONS

Year-round vitamin D deficiency was extremely common in South Asian women. These findings pose great health threats regarding the adverse effects of vitamin D deficiency in pregnancy and warrant urgent vitamin D public health policy and action.

Rickets: Part I

Rickets is characterized by impaired mineralization and ossification of the growth plates of growing children caused by a variety of disorders, the most frequent of which is nutritional deficiency of vitamin D. Despite ample knowledge of its etiology and the availability of cost-effective methods of preventing it, vitamin D deficiency rickets remains a significant problem in developing and developed countries. This two-part review covers the history, etiology, pathophysiology and clinical and radiographical findings of vitamin D deficiency rickets. Other less frequent causes of rickets and some of the disorders entering into the differential diagnoses of rickets are also considered. Controversial issues surrounding vitamin D deficiency include determination of what constitutes vitamin D sufficiency and the potential relationship between low levels of vitamin D metabolites in many individuals and unexplained fractures in infants.

Vitamin D and calcium status in urban children attending an ambulatory clinic service in the United Arab Emirates

Background: Maintaining a normal vitamin D status is important for both skeletal and extra-skeletal health. Recent data show that vitamin D deficiency is endemic in women residing in the Arabian Gulf and is common in pregnant women and their newborns. The purpose of this study was to establish the vitamin D and calcium status of children in an urban ambulatory pediatric clinic in Abu Dhabi to determine for the prevalence of vitamin D deficiency in this cohort.

Methods: Patients were recruited prospectively from the pediatric outpatient clinic visits, if they were having blood taken for laboratory investigations other than those related to vitamin D and calcium status. The vitamin D status was compared between 4 age groups (0–0.9 y, 1–1.9 y, 2–7.9 y and 8 -14 y) using the following definitions: deficiency < 25 nmol/l, insufficiency 25–50 nmol/l and sufficiency > 50 nmol/l.

Results: A total of 183 children were included in the study. The percentage of females and males in the deficient range was 21% and 16% respectively, while 32% and 46% of females and males respectively were vitamin D sufficient. The highest prevalence of vitamin D deficiency occurred in the 8–14 y old age group with 31.2% being deficient.

Conclusions: The study highlights that in an ambulatory pediatric clinic population, peri-pubescent children are most at risk of vitamin D deficiency. This age group is often not considered in the discussion for the need for vitamin D supplementation. Serious consideration should be given to including vitamin D supplementation in a school public health program in the UAE.

[Vitamin D: pathophysiology and clinical applicability in paediatrics]

Vitamin D has always been associated with calcium -phosphate metabolism, but vitamin D receptors or its metabolites have been found in different body cells, indicating a possible involvement in other physiological mechanisms. Vitamin D deficiency has been associated with an increased risk of infections, autoimmune diseases, diabetes, metabolic syndrome, obesity, asthma and certain neurological diseases such as schizophrenia. Currently there are different techniques for measuring 25 (OH) cholecalciferol in blood, but the results are variable and controversial. It is important to achieve standardization of these techniques to be able to compare the results obtained in different studies. Normal physiological vitamin D levels have not yet been established, but they must be higher than 20 ng/ml (50 nmol/l) in order to perform it physiological function. It is still under discussion on how to achieve these minimum levels. Since the main source of vitamin D is sunlight, we should look for strategies that do not contradict the messages of prevention of skin cancer. In recent years, recommendations for vitamin D intake have changed, involving prophylactic activities carried out in Primary Care. This manuscript reviews the physiology, actions, laboratory determination, desirable levels, and vitamin D intake recommendations, and it highlights many questions raised by new research.

Rickets-vitamin D deficiency and dependency

Rickets is an important problem even in countries with adequate sun exposure. The causes of rickets/osteomalacia are varied and include nutritional deficiency, especially poor dietary intake of vitamin D and calcium. Non-nutritional causes include hypophosphatemic rickets primarily due to renal phosphate losses and rickets due to renal tubular acidosis. In addition, some varieties are due to inherited defects in vitamin D metabolism and are called vitamin D dependent rickets. This chapter highlights rickets/osteomalacia related to vitamin D deficiency or to inherited defects in vitamin D metabolism. Hypophosphatemic rickets and rickets due to renal tubular acidosis are discussed in other sections of the journal.

Vitamin D in pregnancy and lactation in humans

Concerns exist about the adequacy of vitamin D in pregnant and lactating women. This review assesses the evidence that maternal vitamin D status influences maternal, fetal, and breast-fed infant bone health; maternal adverse outcomes (preeclampsia, gestational diabetes, obstructed labor, and infectious disease); fetal adverse outcomes (growth, gestational age, and developmental programming); and infant adverse outcomes. The evidence for all of these outcomes is contradictory (except for maternal infectious disease) and lacking causality; thus, it is inconclusive. The 2011 Dietary Reference Intakes for vitamin D and their implications for assessing vitamin D status are discussed. An estimated 5% to 29% of American pregnant women may have inadequate vitamin D status, with the higher prevalence in African Americans. Little is known about the prevalence of inadequacy in American lactating women. Research needs are also identified, especially the need for rigorous and well-designed randomized clinical trials to determine the role of vitamin D in nonbone health outcomes in pregnancy and lactation.

Prevention of Vitamin D deficiency in infancy: daily 400 IU vitamin D is sufficient

Summary

Composition and use of puppy milk replacers in German Shepherd puppies in the Netherlands

Enostosis or eosinophilic panosteitis is a common disease in young growing large-breed dogs, such as the German Shepherd, and the risk of developing the disease by 3-4 months of age is increased by a high calcium intake. The aim of the study was to investigate whether German Shepherd puppies raised on milk replacers receive more calcium and/or vitamin D than their requirements in the pre-weaning period and thus are at increased risk of developing skeletal diseases. To this end, we surveyed German Shepherd breeders in the Netherlands about the use of puppy milk replacers (PMR). The metabolizable energy, calcium, phosphorus and vitamin D content of the eight most used PMR were compared with that of bitch milk, as reported in the literature. The protein and fat content of most PMR were somewhat lower (range 24.4-33.2 g per 100 g on dmb and 18.3-37.5 g per 100 g on dmb respectively) compared with bitch milk (31.9 and 40.2 g on dmb respectively). The vitamin D content of one of the PMR samples was sevenfold the level recommended by the NRC (Nutrient Requirements of Dogs and Cats, National Academy Press, 2006) and threefold the average level of bitch milk. The clinical relevance of this high amount is questionable, as bitch milk contains mainly 25-hydroxy-vitamin D [3843 μg (96.1 IU) per 100 g on dmb] and only limited amounts of vitamin D [524 μg (13.3 IU) per 100 g on dmb], as was determined in this study. Dutch German Shepherd breeders tended to overfeed their puppies. We calculated that misguided use of PMR can increase the risk of excessive calcium, phosphorus and possibly vitamin D intake during a vulnerable period, potentially giving rise to bone and cartilage problems later in life.

Nutritional rickets

Nutritional rickets (NR) is still the most common form of growing bone disease despite the efforts of health care providers to reduce the incidence of the disease. Today, it is well known that the etiology of NR ranges from isolated vitamin D deficiency (VDD) to isolated calcium deficiency. In Turkey, almost all NR cases result from VDD. Recent evidence suggests that in addition to its short- or long-term effects on skeletal development, VDD during infancy may predispose the patient to diseases such as diabetes mellitus, cancer and multiple sclerosis. Among the factors responsible for the high prevalence of VDD in developing countries and its resurgence in developed countries is limited sunshine exposure due to individuals' spending more time indoors (watching television and working on computer) or avoiding sun exposure intentionally for fear of skin cancer. Traditional clothing (covering the entire body except the face and hands) further limits the exposure time to sunlight and, thus, decreases the endogenous synthesis of vitamin D. In Turkey, maternal VDD and exclusive breastfeeding without supplementation were reported to be the most prominent reasons leading to NR. The diagnosis of NR is established by a thorough history and physical examination and confirmed by laboratory evaluation. Recent reports draw attention to the supplemental doses of vitamin D required to achieve a serum 25-hydroxyvitamin D level of at least 20 ng/ml (50 nmol/l) - the serum concentration that is needed to optimize absorption of dietary calcium and to suppress excessive secretion of parathyroid hormone. This type of prevention will also reduce fracture risk as well as prevent long-term negative effect of vitamin D insufficiency.

Vitamin D deficiency in pregnant women and their newborns as seen at a tertiary-care center in Karachi, Pakistan

OBJECTIVE

To estimate the prevalence of vitamin D deficiency among pregnant women in Karachi, Pakistan; correlate maternal and cord blood vitamin D deficiency; and assess possible predictors of vitamin D deficiency.

METHODS

This observational, analytical, cross-sectional study was conducted with 50 consecutive women in labor presenting with a singleton term pregnancy at a large tertiary center in Karachi. Data were recorded on a special form, maternal blood was taken before delivery and cord blood was taken at delivery. All blood samples were analyzed for 25-hydroxy vitamin D levels. Comparisons were made using the Χ(2) test.

RESULTS

The mean vitamin D levels were 24 ng/mL for the participants and 20 ng/mL for the newborns. Vitamin D sufficiency was noted in 11 (22%), insufficiency in 16 (32%), and deficiency in 23 (46%) of the 50 participants whereas sufficiency and deficiency, respectively, were noted in 6 (12%) and 44 (88%) of the newborns. There was a positive correlation between the vitamin D levels in maternal and cord blood (r=0.03; P<0.003). Maternal vitamin D levels were significantly affected by sunlight exposure (P<0.007) and quality of diet P<0.01).

CONCLUSION

Vitamin D deficiency is high among pregnant urban Pakistani women and their newborns. This public health problem needs urgent attention.