[Prevalence of vitamin D deficiency and associated factors in women and newborns in the immediate postpartum period]

Prevalence of vitamin D deficiency in exclusively breastfed infants at Charoenkrung Pracharak Hospital

BACKGROUND

Vitamin D deficiency is a common problem in exclusively breastfed infants, with supplementation recommended by various international medical organizations. However, in Thailand, no advice for routine vitamin D supplementation is available. Thus, this study investigated the prevalence of vitamin D deficiency and its associated factors in exclusively breastfed infants in Bangkok, Thailand.

AIM

To investigated the prevalence of vitamin D deficiency and its associated factors in exclusively breastfed infants in Bangkok, Thailand.

METHODS

This descriptive observational cross-sectional study assessed 109 4-month-old infants at Charoenkrung Pracharak Hospital from May 2020 to April 2021. The 25-OH vitamin D level of the infants was measured using an electrochemiluminescence binding assay. Vitamin D deficiency was defined as 25-OH level < 20 ng/mL, with vitamin D insufficiency 20-30 ng/mL. The sun index and maternal vitamin D supplementation data were collected and analyzed using the independent t-test, univariate logistic regression, and multivariate logistic regression to identify the associated factors.

RESULTS

The prevalences of vitamin D deficiency and vitamin D insufficiency were 35.78% and 33.03%, respectively with mean serum 25-OH vitamin D levels in these two groups 14.37 ± 3.36 and 24.44 ± 3.29 ng/mL. Multivariate logistic regression showed that the main factors associated with vitamin D status were maternal vitamin D supplementation and birth weight, with crude odds ratios 0.26 (0.08-0.82) and 0.08 (0.01-0.45), respectively. The sun index showed no correlation with the 25-OH vitamin D level in exclusively breastfed infants (r = -0.002, P = 0.984).

CONCLUSION

Two-thirds of healthy exclusively breastfed infants had hypovitaminosis D. Vitamin D supplementation prevented this condition and was recommended for both lactating women and their babies.

Relationship between Lifestyle and Residence Area with 25(OH)D Levels in Older Adults

The aim of this study was to investigate whether the habitat of older adults living in the urban and rural areas is a contributing factor to altered serum 25(OH)D levels. An analytical, cross-sectional research with a quantitative approach was conducted in the upper backwoods of Paraíba with older adults registered at the Reference Center for Social Assistance (CRAS), addressing residents of both rural area (n = 41) and urban area (n = 43) who were randomly chosen to participate in the study. Data collection took place between January and February 2020. Higher rates of handgrip strength were observed in rural older adults (29.22 ± 8.92 Kgf) with serum 25(OH)D levels in the range of 30 to 40 ng/mL when compared to older adults with concentrations below 30 ng/mL (21.82 ± 5.00 Kgf) and above 40 ng/mL (23.47 ± 6.88 Kgf). Older people living in the urban area, with 25(OH)D levels above 40 ng/mL, presented a lower muscle power index when compared to individuals with vitamin levels from 21 to 29 ng/mL (17.40 ± 6.34 s; 15.33 ± 2.00 s). The urbanization associated with 25(OH)D levels can cause changes in skeletal and respiratory muscle strength, because the habitat associated with 25(OH)D levels affects the parameters of muscle strength of the upper limbs for older adults living in a rural area and the muscle strength of the lower limbs for those living in an urban area.

Deficiency and Insufficiency of Vitamin D in Women of Childbearing Age: A Systematic Review and Meta-analysis

OBJECTIVE

 To estimate the prevalence of inadequate vitamin D level and its associated factors for women of childbearing age in Brazil.

METHODS

 A systematic review was conducted (last updated May 2020). Meta-analyses were performed using the inverse-variance for fixed models with summary proportion calculation by Freeman-Tukey double arcsine. Reporting and methodological quality were assessed using the Joanna Briggs Institute tool for prevalence studies.

RESULTS

 Our review identified 31 studies, comprising 4,006 participants. All the studies had at least one weakness, mainly due to the use of convenience sampling and small sample size. The overall prevalence of vitamin D deficiency, insufficiency, and both deficiency and insufficiency were 35% (confidence interval, 95%CI: 34-37%), 42% (95%CI: 41-44%), and 72% (95%CI: 71-74%), respectively.

CONCLUSION

 Although the magnitude of the prevalence of inadequate levels of vitamin D is uncertain, the evidence suggests that presence of vitamin D deficiency or insufficiency in women of reproductive age can cause moderate to severe problems.

Vitamin D Nutritional Status of Chinese Pregnant Women, Comparing the Chinese National Nutrition Surveillance (CNHS) 2015-2017 with CNHS 2010-2012

Optimal vitamin D (vitD) status is beneficial for both pregnant women and their newborns. The aim of this study was to evaluate the vitamin D status of Chinese pregnant women in the latest China Nutrition and Health Surveillance (CNHS) 2015-2017, analyze the risk factors of vitamin D deficiency (VDD), and compare them with those in CNHS 2010-2012. Serum 25 hydroxyvitamin D (25(OH)D) was measured by ELISA method. City type, district, latitude, location, age, vitamin D supplements intake, education, marital status, annual family income, etc., were recorded. The median 25(OH)D concentration was 13.02 (10.17-17.01) ng/mL in 2015-2017, and 15.48 (11.89-20.09) ng/mL in 2010-2012. The vitamin D sufficient rate was only 12.57% in 2015-2017, comparing to 25.17% in 2010-2012. The risk factors of vitamin D inadequacy (25(OH)D < 20 ng/mL) in 2015-2017 were not exactly consistent with that in 2010-2012. The risk factors included season of spring (p < 0.0001) and winter (p < 0.001), subtropical (p < 0.001), median (p < 0.0001) and warm temperate zones (p < 0.0001), the western (p = 0.027) and the central areas (p = 0.041), while vitD supplements intake (p = 0.021) was a protective factor in pregnant women. In conclusion, vitD inadequacy is very common among Chinese pregnant women. We encourage pregnant women to take more effective sunlight and proper vitD supplements, especially for those from the subtropical, warm and medium temperate zones, the western and the central, and in the seasons of spring and winter.

Vitamin D Status in Infants during the First 9 Months of Age and its Effect on Growth and Other Biochemical Markers: A Prospective Cohort Study

Background:

Despite food fortification policies in many countries and recommendations for Vitamin D supplementation of at-risk groups, Vitamin D deficiency (VDD) and infantile rickets remain major public health challenges in many developed and developing countries.

Materials and Methods:

Ninety-six participants at birth were enrolled and followed up until 9 months of age. Serum 25OHD was estimated in cord blood at birth and at 14 ± 1 weeks of life. Seventy-seven participants were followed up at 9 months for estimation of serum 25OHD, parathyroid hormone (PTH), alkaline phosphatase (ALP), calcium, and phosphorus. VDD was defined as serum 25OHD <15 ng/mL as per USIOM guidelines.

Results:

Serum 25OHD levels at 9 months of age (15.78 ± 8.97 ng/mL) were significantly increased in comparison to the level of 3 months of age (14.04 ± 7.10 ng/mL) and at birth (8.94 ± 2.24 ng/mL). At birth, all the participants (77) were deficient in 25OHD levels. It was found that 16/94 (17%) and 19/77 (24.7%) participants at 3 and 9 months of age, respectively, became Vitamin D sufficient without any Vitamin D supplementation. There was a significant inverse correlation between serum 25OHD and PTH concentration (r = −0.522, P < 0.001), serum 25OHD and ALP (r = −0.501, P < 0.001). It was found that reduction in serum Vitamin D level to <10.25 ng/mL results in a surge of serum PTH.

Conclusion:

VDD is common from birth to 9 months of age but incidence decreases spontaneously even without supplementation. Furthermore, a large number of babies may be falsely labeled as Vitamin D deficient with currently followed cutoffs. Hence a new cutoff for VDD needs to be established for neonates and infants.

Association between vitamin D plasma concentrations and VDR gene variants and the risk of premature birth

Background

Premature birth is the main cause of mortality in children under 1 year, and vitamin D deficiency during gestation is associated with prematurity. The effects of vitamin D are mediated by its receptor, which is encoded by the VDR gene. VDR variants—such as single nucleotide variation (SNV)—are associated with increased risk of prematurity, but there are conflicting results. We evaluated serum vitamin D concentrations and the frequency of TaqI/A > G, BsmI/C > T, ApaI/C > A, and FokI/A > T VDR variants in mothers and preterm (PTN) and full-term (FTN) newborns.

Methods

We conducted a case-control study comprising 40 pairs of mothers and their PTNs (gestational age < 32 weeks and/or weight < 1500 g), and 92 pairs of mothers and FTNs as controls. Genotyping was performed by real-time PCR, and plasma vitamin D concentrations were measured by electrochemiluminescence.

Results

Vitamin D levels were significantly lower in PTN mothers. Genotypes TaqI/GG and BsmI/TT, and haplotypes AAG (TaqI/A-ApaI/A-FokI/G) and GCA (TaqI/G-ApaI/C-FokI/A) were significantly more frequent in PTN mothers, and genotypes TaqI/AG, ApaI/AA, and FokI/AG resulted in significantly lower vitamin D levels. Genotypes BsmI/TT and ApaI/AA were associated with vitamin D deficiency and 2.36 and 7.99 times greater likelihood of PTB, respectively. Vitamin D levels were also lower in PTNs, although it was not statistically significant. Genotypes BsmI/TT, ApaI/AA, and FokI/GG, and haplotype GAG (TaqI/G-ApaI/A-FokI/G) were significantly more frequent in PTNs. Those with FokI/GG genotypes had significantly lower vitamin D levels.

Conclusions

VDR variants contribute to variations in vitamin D concentrations and the increased risk of prematurity.

Changes in the total ozone content over the period 2006 to 2100 and the effects on the erythemal and vitamin D effective UV doses for South America and Antarctica

Recent studies show that the ozone layer will recover by the middle part of this century. This is a significant result arising from the Montreal Protocol, and highlights the success of this environmental protection agreement. Climate change projections show that Total Ozone Content (TOC) levels will increase significantly by the end of this century, mainly at higher latitudes. This increase may result in a reduction of the adverse effects of UV radiation overexposure. By contrast, reduced UV radiation levels at the surface of the Earth can result in reduced levels of vitamin D synthesis among the inhabitants of these regions. In this study we provide estimates for the UVI, erythemal, and vitamin-D weighted daily doses for ten different locations in South America and Antarctica. Our calculations were based on ozone projections provided by climate models set forth in the last IPCC report. Results show that the increase of TOC levels in middle and high latitude regions may result in decreased UVI and UV doses throughout the century. In high latitudes, erythemal doses and vitamin D synthesis doses may be reduced by up to 22 and 39%, respectively, if anthropogenic emissions continue to rise throughout the century. Furthermore, there may be reductions of up to 9 and 12%, respectively, in mid-latitudes (20°S to 35°S). Significant variations at Equatorial sites were not observed. In most of South America, the attenuation in UVR caused by increases in TOC during the 21^st century is neither enough to promote protective effects from this radiation, nor for the lack of UVR for vitamin D synthesis. The incidence of UVR in tropical and sub-tropical areas of the continent will continue to be a public health risk for the entire 21^st century during all seasons, regardless of the climatic scenarios. Our results can be used as an important tool for health studies focusing on the excess and/or lack of sun exposure.

Vitamin D sufficiency in young Brazilian children: associated factors and relationship with vitamin A corrected for inflammatory status

OBJECTIVE

To assess sociodemographic, nutritional and health conditions associated with vitamin D sufficiency among young Brazilian children living at different latitudes.

DESIGN

Cross-sectional analysis with a four-level model of inflammation to correct micronutrient concentrations. Prevalence ratios (PR; 95 % CI) were estimated for factors associated with vitamin D sufficiency (≥50 nmol/l), adjusting for child's sex, age, skin colour, stunting and vitamin A+D supplementation.

SETTING

Primary health-care units in four Brazilian cities located at lower (7°59'26·9016″S and 9°58'31·3864″S) and higher latitudes (16°41'12·7752″S and 30°2'4·7292″S).

PARTICIPANTS

In total 468 children aged 11-15 months were included in the analysis.

RESULTS

Only 31·8 % of children were vitamin D sufficient (concentration <30 nmol/l and <50 nmol/l among 32·9 and 68·2 %, respectively). Living at higher latitudes was associated with reduced prevalence of vitamin D sufficiency compared with lower latitudes (PR = 0·65; 95 % CI 0·49, 0·85). Maternal education ≥9 years positively influenced a sufficient vitamin D status in children. After correction for inflammatory status, each increase of 1 µmol/l in vitamin A concentration was associated with a 1·38-fold higher prevalence of vitamin D sufficiency (95 % CI 1·18, 1·61). Progressive decline in the prevalence of vitamin D sufficiency was associated with marginal and deficient status of vitamin A (Ptrend = 0·001).

CONCLUSIONS

Lower latitude, higher maternal education and vitamin A concentration were positively associated with vitamin D sufficiency in young Brazilian children. These findings are relevant for planning public health strategies for improving vitamin D status starting in early infancy.

Prevalence of vitamin D deficiency in cord blood of newborns and the association with maternal vitamin D status

Vitamin D deficiency is common in Southeast Asia but there are limited data in pregnant women and neonates. This study aimed to determine the prevalence of vitamin D deficiency in cord blood of newborns and the association with maternal vitamin D status. A total of 94 pregnant women and their neonates were included. Clinical data and venous maternal blood for calcium, phosphate, albumin, alkaline phosphatase, magnesium, intact parathyroid hormone (iPTH), and vitamin D (25OHD) were obtained on the day of labor. Cord blood was collected following delivery to evaluate vitamin D status of newborns. Mean serum maternal and cord blood 25OHD levels were 25.42 ± 8.07 and 14.85 ± 5.13 ng/mL. The prevalence of vitamin D deficiency (25OHD < 12 ng/mL) and insufficiency (25OHD 12-20 ng/mL) in cord blood of newborns were 20.2 and 69.1%, respectively. There was a significant correlation between maternal and cord blood vitamin D levels (r = 0.86; P < 0.001). The factors associated with cord blood vitamin D deficiency were low maternal 25OHD level and no vitamin D supplement during pregnancy.

CONCLUSION

There is a high prevalence of vitamin D deficiency among Thai neonates. Adequate prenatal vitamin D supplementation should be implemented as routine antenatal care. What is Known: • Vitamin D deficiency is prevalent in Southeast Asia. • There are widespread vitamin D deficiency among Thai populations including pregnant women. What is New: • There is a high prevalence of vitamin D deficiency among Thai neonates. • The factors associated with cord blood vitamin D deficiency are low maternal vitamin D level and no vitamin D supplement during pregnancy.