Bone mineral density at age 7 years does not associate with adherence to vitamin D supplementation guidelines in infancy or vitamin D status in pregnancy and childhood: an Odense Child Cohort study

Sex-specific effects of a Mediterranean diet on lower limb bone strength in Polish children

Lifestyle factors have the potential to influence bone health in various ways, whether positively or negatively. As osteoporosis is believed to originate in early years, it is therefore essential to indicate factors that may positively affect bone health during childhood. The aim of our study was to investigate the effects of early and current diet, vitamin D supplementation, and BMI z-score on bone properties in a group of children aged 3-7 years. A cross-sectional sample of 205 preschoolers and their parents participated in the study. Dietary assessment was made using a modified version of the Polish-adapted Mediterranean Diet score (MVP-aMED) on the basis of the data from food frequency questionnaire (FFQ), filled out by the parents. Quantitative ultrasound (QUS) was used in the assessment of bone properties. In the sex-stratified analysis, significant associations were observed between MVP-aMED score (β = 0.193, 95 % CI: 0.005, 0.237; p = 0.04), BMI z-score (β = -0.318, 95 % CI: -1.455, -0.039; p = 0.04) and QUS z-score, exclusively among girls. After adjustment, only the relationship with diet remained significant (β = 0.209, 95 % CI: 0.007, 0.255; p = 0.04), suggesting that a higher adherence to the Mediterranean Diet may be associated with better bone properties in girls aged 3-7 years old. Our results emphasize the importance of fostering healthy dietary habits and maintaining proper weight in children in order to promote optimal bone development.

Insufficient Bone Mineralization to Sustain Mechanical Load of Weight in Obese Boys: A Cross-Sectional Study

CONTEXT

The increase in bone mineral content (BMC) and density (BMD) measured by dual-energy x-ray absorptiometry (DXA) in obese children may not sustain the mechanical load associated with weight, and the factors influencing bone mineralization are not well known.

OBJECTIVE

We described bone mineralization in boys with overweight/obesity and leanness in relation to body composition.

METHODS

Cross-sectional study in the Pediatric Endocrinology Unit of Angers University Hospital with 249 overweight/obese boys aged 8-18 who underwent DXA and insulin, testosterone, and IGF-1 measurements. Bone mineralization was compared with data from 301 lean boys of similar age and height from NHANES 2011-2015, using the same DXA model. Path analyses were performed to evaluate factors associated with total body less head (TBLH) BMC.

RESULTS

The mean age- and height-adjusted difference in TBLH BMC between obese and lean boys was 241 ± 20 g/cm2. Each 1 kg/m2 increase in BMI was associated with +39 ± 6 g of TBLH BMC in lean subjects vs + 25 ± 3 g in obese subjects (P < .05). Each 1 kg/m2 increase in lean BMI (LBMI) was associated with +78 ± 5 g of TBLH BMC in lean and obese boys, and each 1 kg/m2 increase in fat mass index (FMI) was associated with a decrease of 9 ± 3 g of TBLH BMC. The TBLH BMC was directly positively influenced by LBMI and indirectly and positively influenced by IGF-1, testosterone, and insulin (mediated through height and LBMI). FMI indirectly influenced TBLH BMC, both positively through LBMI and negatively through its negative impact on IGF-1 and testosterone.

CONCLUSION

The increase in bone mineralization in obese children does not adapt to the increase in body mass.

Adherence to vitamin D supplementation guidelines in children under five years of age: a systematic literature review

PURPOSE

Despite the presence of guidelines on vitamin D supplementation in infants and young children, little is known about parental adherence to their recommendations. This review aims to summarise the evidence from observational studies investigating adherence to vitamin D supplementation guidelines in children under five years of age.

METHODS

Databases of PubMed, Scopus, Web of Science, and CINAHL were searched from January 2000 until July 2022. Qualitative data synthesis was used to summarise evidence on supplementation adherence. The adherence rate was categorised as low, moderate, and high if it was ≤ 50%, between 50 and 70%, and ≥ 70%, respectively.

RESULTS

Eleven studies investigating adherence to eight different vitamin D supplementation guidelines from European countries, USA and Canada were included. The majority of studies were cross-sectional and conducted among infants. Overall, the adherence rate ranged between 14.29% and 95.6%. Low, moderate, and high adherence to supplementation guidelines were reported in six, three, and two studies, respectively.

CONCLUSION

There is generally poor adherence to vitamin D supplementation guidelines in children under five years of age. Nevertheless, the evidence comes from a limited number of studies, mainly conducted in infants, with high methodological heterogeneity in terms of the vitamin D supplementation guideline assessed and the definition of supplementation adherence in the study population. Further research is warranted to identify effective health promotion interventions to increase supplementation adherence and reduce the risk of vitamin D deficiency at this critical life stage.

Early Life Programming of Skeletal Health

PURPOSE OF REVIEW

Increasing bone mineral accrual during childhood might delay the onset of osteoporosis. We discuss the scientific evidence for early life approaches to optimising skeletal health.

RECENT FINDINGS

There is an ever-growing body of evidence from observational studies suggesting associations between early life exposures, particularly during foetal development, and bone mineral density (BMD). The findings of such studies are often heterogeneous, and for some exposures, for example, maternal smoking and alcohol intake in pregnancy or age at conception, intervention studies are not feasible. The most frequently studied exposures in intervention studies are calcium or vitamin D supplementation in pregnancy, which overall suggest positive effects on offspring childhood BMD. Maternal calcium and/or vitamin D supplementation during pregnancy appear to have positive effects on offspring BMD during early childhood, but further long-term follow-up is required to demonstrate persistence of the effect into later life.

Vitamin D status in pregnancy and childhood associates with intelligence quotient at age 7 years: An Odense child cohort study

OBJECTIVES

Animal studies indicate a key role for vitamin D in brain development and function, but observational studies in humans only suggests a borderline positive association between prenatal vitamin D exposure and cognitive development in the offspring. Knowledge gaps include insights in exposure time window and differences by sex for the association. We aimed to investigate the association between blood concentrations of serum 25-hydroxyvitamin D measured at four different time points and intelligence quotient score at the age of 7 years, including analyses spilt by child sex.

METHODS

In Odense child cohort, we included 1404 mother-child pairs with serum 25-hydroxyvitamin D data from early pregnancy to age 7 years. Full-scale intelligence quotient was assessed with Wechsler Intelligence Scale for Children - fifth edition. Associations were adjusted for maternal education, pre-pregnancy body mass index, gestational age, sex and head circumference. Subanalyses stratified by sex were performed.

RESULTS

The median (interquartile range) serum 25-hydroxyvitamin D in cord was 45.88 (31.15-61.08) nmol/L; early pregnancy, 66.45 (51.29-78.74); late pregnancy, 79.13 (59.69-97.31); 7 years, 66.29 (53.45-80.23) nmol/L. The mean (standard deviation) full-scale intelligence quotient was 99.44 (11.98). In adjusted analyses, cord serum 25-hydroxyvitamin D < 50 nmol/L was associated with 2.2 points lower full-scale intelligence quotient compared to the reference (50-75 nmol/L) in boys, β = -2.2; 95% confidence interval = [-4.3, -0.1], p = 0.039. The same association with full-scale intelligence quotient was found for early pregnancy serum 25-hydroxyvitamin D, β = -2.5 [-4.6, -0.3], p = 0.025, primarily driven by an association in boys, β = -4.0 [-7.2, -0.8], p = 0.015; and for serum 25-hydroxyvitamin D at 7 years in girls, β = -3.0 [-6.0, -0.1], p = 0.042.

CONCLUSION

In this cohort, serum 25-hydroxyvitamin D < 50 nmol/L in both early gestation and cord blood in boys and current serum 25-hydroxyvitamin D < 50 nmol/L in girls were independent risk factors for two to four points lower full-scale intelligence quotient at the age of 7 years. Vulnerability to hypovitaminosis D, especially in pregnancy, may relate to child sex.