Vitamin D Intake and Status in 6-Year-Old Icelandic Children Followed up from Infancy.

High serum 25-hydroxyvitamin D (25(OH)D) levels have been observed in infants in Nordic countries, likely due to vitamin D supplement use. Internationally, little is known about tracking vitamin D status from infancy to childhood. Following up 1-year-old infants in our national longitudinal cohort, our aims were to study vitamin D intake and status in healthy 6-year-old Icelandic children (n = 139) and to track vitamin D status from one year of age. At six years, the mean 25(OH)D level was 56.5 nmol/L (SD 17.9) and 64% of children were vitamin D sufficient (25(OH)D ≥ 50 nmol/L). A logistic regression model adjusted for gender and breastfeeding showed that higher total vitamin D intake (Odds ratio (OR) = 1.27, 95% confidence interval (CI) = 1.08-1.49), blood samples collected in summer (OR = 8.88, 95% CI = 1.83-43.23) or autumn (OR = 5.64, 95% CI = 1.16-27.32) compared to winter/spring, and 25(OH)D at age one (OR = 1.02, 95% CI = 1.002-1.04) were independently associated with vitamin D sufficiency at age six. The correlation between 25(OH)D at age one and six was 0.34 (p = 0.003). Our findings suggest that vitamin D status in infancy, current vitamin D intake and season are predictors of vitamin D status in early school age children. Our finding of vitamin D status tracking from infancy to childhood provides motivation for further studies on tracking and its clinical significance.

Vitamin D intake and status in 12-month-old infants at 63-66° N.

The objective was to assess the vitamin D status in healthy 12-month-old infants in relation to quantity and sources of dietary vitamin D, breastfeeding and seasons. Subjects were 76 12-month-old infants. Serum levels of 25-hydroxyvitamin D (25(OH)D) ≥ 50 nmol/L were considered indicative of vitamin D sufficiency and 25(OH)D < 27.5 nmol/L as being indicative of increased risk for rickets. Additionally, 25(OH)D > 125 nmol/L was considered possibly adversely high. Total vitamin D at 9-12 months (eight data collection days) included intake from diet and supplements. The mean ± SD of vitamin D intake was 8.8 ± 5.2 µg/day and serum 25(OH)D 98.1 ± 32.2 nmol/L (range 39.3-165.5). Ninety-two percent of infants were vitamin D sufficient and none at increased risk for rickets. The 26% infants using fortified products and supplements never/irregularly or in small amounts had lower 25(OH)D (76.8 ± 27.1 nmol/L) than the 22% using fortified products (100.0 ± 31.4 nmol/L), 18% using supplements (104.6 ± 37.0 nmol/L) and 33% using both (110.3 ± 26.6 nmol/L). Five of six infants with 25(OH)D < 50 nmol/L had no intake of supplements or fortified products from 0 to 12 months. Supplement use increased the odds of 25(OH)D > 125 nmol/L. Breastfeeding and season did not affect vitamin D status. The majority of infants were vitamin D sufficient. Our findings highlight the need for vitamin D supplements or fortified products all year round, regardless of breastfeeding.

Iron status and developmental scores in 6-year-olds highlights ongoing need to tackle iron deficiency in infants.

AIM: To investigate iron status and developmental scores at 6 years of age in a population with decreased prevalence of iron deficiency in infancy. Iron status at 6 years and tracking from 12 months were also studied. METHODS: Children (n = 143) born in Iceland in 2005 were followed up at the age of six. Motor and verbal development was assessed by a parental questionnaire, and iron status was assessed by Hb, MCV and serum ferritin (SF). Iron depletion was defined as SF <15 µg/L and deficiency as MCV <76 fL and SF <15 µg/L. RESULTS: Iron depletion was observed in 5.6% of 6-year-olds, and 1.4% were iron deficient. Self-help (subset in motor development) differed by -4.14 (95% CI = -7.61, -0.67), between those iron depleted at 12 months (n = 6) and those nondepleted (n = 102), adjusted for maternal education. The combined motor developmental score seemed lower in iron depleted infants, although of borderline significance (p = 0.066). MCV concentration tracked from 12 months to 6 years (r = 0.31, p < 0.002), but Hb and SF did not. CONCLUSION: Improved iron status at 12 months and 6 years has diminished the public health threat associated with iron depletion in the population studied, but iron depletion and development still associate weakly. Action to prevent iron depletion in infancy remains important.

Iron status of one-year-olds and association with breast milk, cow's milk or formula in late infancy.

PURPOSE: Studies on iron status in infancy and early childhood have shown contradicting results concerning prolonged breast-feeding and cow's milk intake. The aim of the present study was to investigate associations between iron status among one-year-olds and feeding, with focus on the type of milk. METHODS: Randomly selected healthy infants were prospectively investigated until 1 year of age in two cohorts born 1995-1996 (n = 114) and 2005 (n = 140). Information on birth data, feeding and growth until 12 months and iron status at 12 months was collected. Data from the two cohorts were pooled and the infants categorized into three groups according to their predominant milk consumption at 9 months of age, that is, breast milk, cow's milk or follow-on formula. RESULTS: The prevalence of iron deficiency was highest in the cow's milk group and lowest in the follow-on formula group. According to a linear model, adjusted for gender, birth weight and exclusive breast-feeding duration, cow's milk consumption was negatively associated with serum ferritin (SF) and formula positively, but breast milk not. Predicted SF (µg/l) = 11.652(intercept) - 5.362(boy) + 0.005 × birth weight (g) + 2.826(exclusively breastfed ≥ 4 months) + 0.027 × formula (ml) - 0.022 × cow's milk (ml) + 0.005 × breast milk (ml). Correction for other dietary factors did not change these results. CONCLUSION: In this pooled analysis, cow's milk intake in late infancy associated negatively, and follow-on formula positively, with iron status. Prolonged partial breast-feeding does not seem to be of importance for iron status. Fortified food seems to improve iron status in late infancy.

Timing of the introduction of complementary foods in infancy: a randomized controlled trial.

OBJECTIVE: To increase knowledge on iron status and growth during the first 6 months of life. We hypothesized that iron status would be better in infants who received complementary foods in addition to breast milk compared with those exclusively breastfed. METHODS: One hundred nineteen healthy term (≥37 weeks) singleton infants were randomly assigned to receive either complementary foods in addition to breast milk from age 4 months (CF) or to exclusive breastfeeding for 6 months (EBF). Dietary data were collected by 3-day weighed food records, and data on iron status and growth were also collected. RESULTS: One hundred infants (84%) completed the trial. Infants in the CF group had higher mean serum ferritin levels at 6 months (P = .02), which remained significant when adjusted for baseline characteristics. No difference was seen between groups in iron deficiency anemia, iron deficiency, or iron depletion. The average daily energy intake from complementary foods of 5-month-olds in the CF group was 36.8 kJ per kg body weight. Infants in both groups grew at the same rate between 4 and 6 months of age. CONCLUSIONS: In a high-income country, adding a small amount of complementary food in addition to breast milk to infants' diets from 4 months of age does not affect growth rate between 4 and 6 months, but has a small and positive effect on iron status at 6 months. The biological importance of this finding remains to be determined.

Nutrition and Iron Status of 1-Year Olds following a Revision in Infant Dietary Recommendations.

A previous study showed low iron status in 12-month-old Icelandic infants associated most strongly with cow's milk intake and growth. Infant dietary recommendations were revised in 2003. This study investigated nutrition and iron status in a new infant cohort. Subjects/Methods. Randomly selected infants were prospectively investigated for diet, anthropometry, and iron status (n = 110-141). Results. Breastfeeding initiation rate was 98%; 38% of 5-month olds were exclusively and 20% of 12-month olds partially breastfed. Formula was given to 21% of 6-month olds and 64% of 12-month olds, but cow's milk to 2.5% and 54.4% of 6- and 12-month olds, respectively. Iron depletion (serum ferritin < 12 µg/L) affected 5.8%, 1.4% were also iron deficient (MCV < 74 fl), and none were anemic (Hb < 105 g/l). Iron status associated negatively with growth and breastfeeding duration and positively with meat and formula intake at 9-12 months, but not with cow's milk. Conclusion. Improved iron status might be explained by a shift from cow's milk to formula in the diet of Icelandic 6-12-month olds. Dietary changes altered associations between foods and iron status.

The relation of fatness to insulin is independent of fitness in 9- but not 15-yr-olds.

PURPOSE: To explore the relationship between varying aerobic fitness (fitness), fatness, and fasting insulin levels in healthy children. METHODS: A population-based sample of 9-yr-old (9YO, 47 boys, 56 girls) and 15-yr-old (15YO, 53 boys, 51 girls) Icelandic children. Body fatness was evaluated via body mass index, waist circumference adjusted for height (waist adj), and sum of four skinfolds. Fitness was assessed with a graded maximal cycle ergometer test. Fasting insulin was measured using an ECLIA. RESULTS: Fasting insulin correlated to all fatness measures (9YO, r = 0.43-0.46, P < 0.001; 15YO, r = 0.30-0.37, P < 0.003) and fitness (9YO, r = -0.29, P = 0.003; 15YO, r = -0.32, P = 0.001). Adjustment for fitness did not affect the relations between fatness and fasting insulin in 9YO (r = 0.33-0.37, P < 0.001); however, only waist adj remained significantly related to fasting insulin (r = 0.24, P = 0.016) in 15YO. Children in the upper half of fitness and fatness split on the median did not differ in fasting insulin from children in the upper half of fitness but lower half of fatness. Fatness was related to fasting insulin in 9YO (r = 0.51-0.54, P = 0.001) and 15YO (r = 0.31-0.35, P = 0.011-0.028) in the lower half of fitness, but no association was observed in the upper half of fitness in either group. CONCLUSION: Fatness has a greater association with fasting insulin than fitness, especially among 9YO; however, fitness attenuates the adverse relation of fatness to fasting insulin in 15YO but does not change it in 9YO. In both age groups, being fitter and fatter does not result in greater fasting insulin than being fitter and leaner, and fatness is primarily associated with fasting insulin in lower-fit children.

Anthropometric predictors of serum fasting insulin in 9- and 15-year-old children and adolescents.

BACKGROUND AND AIM: As the prevalence of overweight and obesity increases, the risk of insulin resistance rises. The aim was to study the association between anthropometric measurements and fasting insulin concentration in a population-based sample of 9- and 15-year-old children and adolescents. METHODS AND RESULTS: Subjects were randomly selected 9- and 15-year-old pupils (n=262) in a cross-sectional, population-based study. Weight and height, waist, hip and mid-arm-circumference and subcutaneous skinfolds were measured using standard procedures. Fasting insulin was measured. In general the mean anthropometric measurements increased across insulin quartiles. Higher fasting insulin concentration was seen in overweight children and adolescents than in those of normal weight (8.3+/-4.4 vs. 4.9+/-3.6 mmol/L and 11.0+/-4.4 vs. 9.0+/-4.2 mmol/L in 9- and 15 year-olds, respectively). The odds ratio for having insulin in the highest quartile (age and gender-specific) was, when compared with the lowest quartile, 7.2 (95% CI 3.0-17.2) for body mass index and 6.9 (2.8-16.7) for waist circumference. Other measurements of body fatness were less predictive. About 14-20% of children defined as being of normal weight had high fasting insulin values, i.e., were in the highest quartile of fasting insulin. CONCLUSIONS: Body fatness is positively related to fasting insulin concentration in 9- and 15-year-old children. A large number of normal-weight individuals with high fasting insulin concentration was observed, and these children could be at increased risk of weight gain, compared with normal-weight individuals with normal fasting insulin concentration.

[Uniparental disomy of chromosome 11 in a patient with Beckwith-Wiedemann syndrome. First reported case in Iceland]. / Tvístaeoa litnings nr. 11 frá föour hjá sjúklingi meo Beckwith-Wiedemann heilkenni. Fyrsta greining á Islandi--Sjúkratilfelli.

Beckwith-Wiedemann syndrome (BWS) is a generalized overgrowth condition as well as regional and organ overgrowth in newborn children. It includes an increased risk of certain embryonal tumours. The aetiology of BWS is complex as different genetic and epigenetic alterations at chromosome region 11p15.5 may occur. We report the first case of paternal uniparental disomy in Beckwith-Wiedemann syndrome in Iceland. The diagnosis of Beckwith-Wiedemann syndrome is important as the risk of malignant tumors makes it mandatory that the children are followed for several years with regular investigations to detect the tumors as early as possible.