The Effects of Vitamin D Supplementation During Infancy on Growth During the First 2 Years of Life

The Relationship Between Vitamin D Intake and Serum 25-hydroxyvitamin D in Young Children: A Meta-Regression to Inform WHO/FAO Vitamin D Intake Recommendations

BACKGROUND

This work was commissioned by the World Health Organization and Food and Agriculture Organization to inform their update on the vitamin D requirements for children aged <4 y.

OBJECTIVES

The objective of this work was to undertake multilevel and multivariable dose-response modeling of serum 25-hydroxyvitamin D (25OHD) to total vitamin D intake in children aged <4 y with the goal of deriving updated vitamin D requirements for young children.

METHODS

Systematically identified randomized controlled trials among healthy children from 2 wk up to 3.9 y of age provided with daily vitamin D supplements or vitamin D-fortified foods were included. Linear and nonlinear random effects multilevel meta-regression models with and without covariates were fitted and compared. Interindividual variability was included by simulating the individual serum 25OHD responses. The percentage of individuals reaching set minimal and maximal serum 25OHD thresholds was calculated and used to derive vitamin D requirements.

RESULTS

A total of 31 trials with 186 data points from North America, Europe, Asia, and Australasia/Oceania, with latitudes ranging from 61°N to 38°S, and with participants of likely mostly light or medium skin pigmentation, were included. In 29 studies the children received vitamin D supplements and in 2 studies the children received vitamin D-fortified milk with or without supplements. The dose-response relationship between vitamin D intake and serum 25OHD was best fitted with the unadjusted quadratic model. Adding additional covariates, such as age, did not significantly improve the model. At a vitamin D intake of 10 μg/d, 97.3% of the individuals were predicted to achieve a minimal serum 25OHD threshold of 28 nmol/L. At a vitamin D intake of 35 μg/d, 1.4% of the individuals predicted to reach a maximal serum 25OHD threshold of 200 nmol/L.

CONCLUSIONS

In conclusion, this paper details the methodological steps taken to derive vitamin D requirements in children aged <4 y, including the addition of an interindividual variability component.

Relationships for vitamin D with childhood height growth velocity and low bone mineral density risk

Objective

To investigate how serum 25-hydroxyvitamin D (25[OH]D) affects height growth velocity and the risk of low bone mineral density (BMD) in children.

Design

A population-based prospective cohort study.

Patients and methods

A total of 10 450 participants with complete follow-up records from a cohort were included in the current study. Serum 25(OH)D concentrations were measured at baseline and 2-year follow-up, and the average of 2-time measurements was used for analysis. Low BMD was defined as calcaneus speed of sound Z-score ≤ -1. The associations of vitamin D with height growth velocity and the risks of incident low BMD were evaluated using adjusted β and risk ratio (RR).

Results

After multivariable adjustment, an inverse L-shaped association between serum 25(OH)D concentrations and height growth velocity was observed, leveling off up to 40-60 nmol/L. Overall, each 10 nmol/L higher serum 25(OH)D concentration was associated with a 0.15 cm/year higher height growth velocity (P < 0.001) and a 7% decreased risk of low BMD [RR (95%CI): 0.93 (0.87~0.98)]. Compared to those with vitamin D deficiency, participants who had sufficient vitamin D had a 22% lower risk for low BMD [RR(95%CI): 0.78 (0.62~0.98)]. However, no significant associations between vitamin D and the risk of low BMD were found in overweight and obese children.

Conclusion

These findings highlight the importance of maintenance of sufficient 25(OH)D concentrations and healthy body weight during childhood in height growth and bone health promotion.

Dietary Supplements among Children Ages 0-3 Years in Poland-Are They Necessary?

(1) Background: One of the ways to prevent nutritional deficiencies may be supplementation. Experts have observed the increased use of dietary supplements, not only in adults but also in children. Considering controversies among dietary supplements and possible errors in children's feeding, the goal of our research was to evaluate use and reasons behind supplementation in terms of children's diet analysis. (2) Methods: Our research involved 507 legal guardians of the youngest children (up to 3 years of age) and was conducted via a questionnaire. (3) Results: 79% of all children received dietary supplements. The analysis of children's diets showed a need to implement omega-3 acids and vitamin D supplementation, which was very low in children. On the other hand, vitamin C, vitamin B, vitamin A, and copper levels were extremely high. (4) Conclusions: Popularity of dietary supplements in Polish children aged 0-3 years old is an omnipresent issue. Although the reasoning behind administering nutritional supplements to children seems justified, considering the supply of vitamin D and omega-3 fatty acids, it seems justified to increase parents' knowledge in this regard in terms of the use and means to choose the best supplement possible, as dietary supplementation should always be tailored to individual needs.

Collagen X Biomarker (CXM), Linear Growth, and Bone Development in a Vitamin D Intervention Study in Infants

Collagen X biomarker (CXM) is suggested to be a biomarker of linear growth velocity. However, early childhood data are limited. This study examines the relationship of CXM to the linear growth rate and bone development, including the possible modifying effects of vitamin D supplementation. We analyzed a cohort of 276 term-born children participating in the Vitamin D Intervention in Infants (VIDI) study. Infants received 10 μg/d (group-10) or 30 μg/d (group-30) vitamin D₃ supplementation for the first 2 years of life. CXM and length were measured at 12 and 24 months of age. Tibial bone mineral content (BMC), volumetric bone mineral density (vBMD), cross-sectional area (CSA), polar moment of inertia (PMI), and periosteal circumference (PsC) were measured using peripheral quantitative computed tomography (pQCT) at 12 and 24 months. We calculated linear growth as length velocity (cm/year) and the growth rate in length (SD unit). The mean (SD) CXM values were 40.2 (17.4) ng/mL at 12 months and 38.1 (12.0) ng/mL at 24 months of age (p = 0.12). CXM associated with linear growth during the 2-year follow-up (p = 0.041) but not with bone (p = 0.53). Infants in group-30 in the highest tertile of CXM exhibited an accelerated mean growth rate in length compared with the intermediate tertile (mean difference [95% CI] -0.50 [-0.98, -0.01] SD unit, p = 0.044) but not in the group-10 (p = 0.062) at 12 months. Linear association of CXM and growth rate until 12 months was weak, but at 24 months CXM associated with both length velocity (B for 1 increment of √CXM [95% CI] 0.32 [0.12, 0.52] cm/yr, p = 0.002) and growth rate in length (0.20 [0.08, 0.32] SD unit, p = 0.002). To conclude, CXM may not reliably reflect linear growth from birth to 12 months of age, but its correlation with growth velocity improves during the second year of life. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Iron status in early childhood is modified by diet, sex and growth: Secondary analysis of a randomized controlled vitamin D trial

BACKGROUND & AIMS

During early childhood the risk of iron deficiency (ID) is high. Serum ferritin serves as a marker of iron status. We explored prevalence of ID and iron deficiency anemia (IDA), and identified determinants of iron status in infants and toddlers.

METHODS

We performed a secondary analysis of the Vitamin D intervention in infants (VIDI) study in Finnish healthy term infants. According to study protocol, at 12- and 24-months of age iron status, growth and dietary intakes were evaluated. ID was defined as serum ferritin <10 μg/L and IDA as serum ferritin <10 μg/L and Hb <112 g/L. For the present study, altogether 766 children provided data (N = 498 infants at 12 months, N = 508 toddlers at 24 months).

RESULTS

ID prevalence increased from 14% in infants to 20% in toddlers. IDA prevalence was 3% at both time points. In infants, ID and IDA were more common in boys than in girls (19% vs. 9%, p = 0.001 and 5% vs. 1%, p = 0.039) but no sex-difference in toddlers was observed. Of infants, 30% had daily iron intake below average requirement of 5 mg/day. Higher daily iron intake per body weight (mg/kg) independently associated with higher infant serum ferritin (B (95% CI) 0.30 (0.04, 0.56), p = 0.026). Correlation between iron intake and ferritin was stronger in infants with ID than in infants without ID. Breastfeeding was more common (63% vs. 35%, p < 0.001) among ID infants than in infants without ID. In toddlers, frequent consumption of milk products independently associated with lower ferritin (B (95% CI) -0.03 (-0.05, -0.01), p = 0.001). Consumption of meat and fish associated with better iron status. Serum ferritin at both time points associated with duration of gestation and growth. The association of growth and ferritin was age-dependent in boys, while in girls, faster growth associated consistently with lower ferritin.

CONCLUSIONS

In Northern European healthy infants and toddlers ID is common. The intake of iron remains below recommendations and food consumption and iron intake associate with iron status. Further studies are warranted to assess significance of ID on child development and clinical health outcomes. The project protocol is registered at ClinicalTrials.gov: NCT01723852.