Background: Dark skin and low exposure to sunlight increase the risk of vitamin D insufficiency in children.

Context and purpose Individual participant data-level meta-regression (IPD) analysis is superior to meta-regression based on aggregate data in determining Dietary Reference Values (DRV) for vitamin D. Using data from randomized controlled trials (RCTs) with vitamin D₃-fortified foods, we undertook an IPD analysis of the response of winter serum 25-hydroxyvitamin (25(OH)D) to total vitamin D intake among children and adults and derived DRV for vitamin D. Methods IPD analysis using data from 1429 participants (ages 2–89 years) in 11 RCTs with vitamin D-fortified foods identified via a systematic review and predefined eligibility criteria. Outcome measures were vitamin D DRV estimates across a range of serum 25(OH)D thresholds using unadjusted and adjusted models. Results Our IPD-derived estimates of vitamin D intakes required to maintain 97.5% of winter 25(OH)D concentrations ≥ 25 and ≥ 30 nmol/L are 6 and 12 µg/day, respectively (unadjusted model). The intake estimates to maintain 90%, 95% and 97.5% of concentrations ≥ 50 nmol/L are 33.4, 57.5 and 92.3 µg/day, respectively (unadjusted) and 17.0, 28.1 and 43.6 µg/day, respectively (adjusted for mean values for baseline serum 25(OH)D, age and BMI). Conclusions IPD-derived vitamin D intakes required to maintain 90%, 95% and 97.5% of winter 25(OH)D concentrations ≥ 50 nmol/L are much higher than those derived from standard meta-regression based on aggregate data, due to the inability of the latter to capture between person-variability. Our IPD provides further evidence that using food-based approaches to achieve an intake of 12 µg/day could prevent vitamin D deficiency (i.e., serum 25(OH)D < 30 nmol/L) in the general population.

Observational studies have linked low vitamin D status to unfavorable cardiometabolic risk markers, but double-blinded vitamin D intervention studies in children are scarce. The aim was to evaluate the effect of different doses of a vitamin D supplement on cardiometabolic risk markers in young healthy Swedish children with fair and dark skin. Cardiometabolic risk markers were analyzed as secondary outcomes of a double-blind, randomized, milk-based vitamin D intervention trial conducted during late fall and winter in 2 areas of Sweden (latitude 63°N and 55°N, respectively) in both fair- and dark-skinned 5- to 7-y-old children. During the 3-mo intervention, 206 children were randomly assigned to a daily milk-based vitamin D₃ supplement of either 10 or 25 µg or placebo (2 µg; only at 55°N). Anthropometric measures, blood pressure, serum 25-hydroxyvitamin D [25(OH)D], total cholesterol, HDL cholesterol, apoA-I, apoB, and C-reactive protein (CRP) were analyzed and non–HDL cholesterol calculated at baseline and after the intervention. At baseline, serum 25(OH)D was negatively associated with systolic and diastolic blood pressure (β = −0.194; 95% CI: −0.153, −0.013; and β = −0.187; 95% CI: −0.150, −0.011, respectively). At follow-up, there was no statistically significant difference in any of the cardiometabolic markers between groups. We could not confirm any effect of vitamin D supplementation on serum lipids, blood pressure, or CRP in healthy 5- to 7-y-old children. The study was registered at clinicaltrials.gov (NCT01741324).

Vitamin D and calcium are essential nutrients with a range of biological effects of public health relevance. This study aimed to validate a short food frequency questionnaire (SFFQ) against a three-day food record (3D record), assessing the intake of vitamin D and calcium in Swedish children during wintertime. In a double-blinded, randomized food-based intervention study on the effect of feeding different daily doses of vitamin D supplement to 5–7-year-old children (n = 85), 79 (93%) participants completed SFFQ1 at baseline and SFFQ2 after the intervention, and 72 were informed to fill in a 3D record. The 28 (39%) children who completed the 3D record were included in this validation study. The baseline level of serum-25 hydroxy vitamin D [S-25(OH)D] was used as a biomarker. The correlation between all three instruments were moderate to strong. SFFQ2 and the 3D record correlated moderately to S-25(OH)D. Bland-Altman analysis showed that SFFQ2 overestimated vitamin D intake by on average 0.6 μg/day, (limits of agreement (LOA) 5.7 and −4.6 μg/day), whereas the intake of calcium was underestimated by on average 29 mg/day, (LOA 808 and −865 mg/day). Finally, the validity coefficient calculated for vitamin D using the method of triad was high (0.75). In conclusion, this SFFQ, assessed by a dietician, is a valid tool to assess dietary vitamin D and calcium intake in groups of young children.

What we eat as infants and children carries long-term consequences. Apart from breastfeeding, the composition of the complementary diet, i.e. the foods given to the infant during the transition from breast milk/infant formula to regular family foods affects the child’s future health. A high intake of protein, a low intake of fruits, vegetables and fish and an unfavorable distribution between polyunsaturated and saturated fats are considered to be associate with health risks, e.g. obesity, type 2 diabetes and dyslipidemia later in life. In a randomized, controlled study from 6 to 18 months of age we will compare the currently recommended, Swedish complementary diet to one based on Nordic foods, i.e. an increased intake of fruits, berries, vegetables, tubers, whole-grain and game, and a lower intake of sweets, dairy, meat and poultry, with lower protein content (30% decrease), a higher intake of vegetable fats and fish and a systematic introduction of fruits and greens. The main outcomes are body composition (fat and fat-free mass measured with deuterium), metabolic and inflammatory biomarkers (associated with the amount of body fat) in blood and urine, gut microbiota (thought to be the link between early diet, metabolism and diseases such as obesity and insulin resistance) and blood pressure. We will also measure the participants’ energy and nutrient intake, eating behavior and temperament through validated questionnaires, acceptance of new and unfamiliar foods through video-taped test meals and assessment of cognitive development, which we believe can be influenced through an increased intake of fish and milk fats, notably milk fat globule membranes (MFGM). If the results are what we expect, i.e. improved body composition and a less obesogenic, diabetogenic and inflammatory metabolism and gut microbiota composition, a more sustainable nutrient intake for future health and an increased acceptance of healthy foods, they will have a profound impact on the dietary recommendations to infants in Sweden and elsewhere, their eating habits later in life and subsequently their long-term health. NCT02634749 . Registration date 18 December 2015.

Background: Breastmilk is the recommended aliment for preterm infants. Milk banks provide donated breastmilk for the neonatal care of preterm infants when mother's own milk is not is available. To avoid pathogen transmission, donated breastmilk is heat-treated according to different procedures before administration. There is varying information on the effect of heat treatment on folate in breastmilk. Sufficient folate intake, however, is essential for normal growth and brain development. This study determined and compared the effects of different heat treatments on breastmilk folate content and pattern of individual folate forms. Materials and Methods: Donated Swedish breastmilk samples were heat-treated according to three procedures: two low temperature treatments (57°C, 23 minutes; 62.5°C, 12 minutes) and a rapid high temperature treatment (heating to 73°C in boiling water). The folate content and pattern were determined before and after treatment by high-performance liquid chromatography. Results: The folate content in 38 untreated Swedish breastmilk samples was 150±46 nmol/L. Two different folate vitamers were detected: 5-methyltetrahydrofolate (78±7%) and tetrahydrofolate (22±7%). Heat treatment affected only tetrahydrofolate stability and decreased folate content by 15–24%; however, the effects on folate content did not differ among the investigated heat treatment procedures. Conclusions: Folate losses during heat treatment of human milk were considered acceptable. Yet, native folate content of heat-treated, non-fortified breastmilk supplied only 25% of the recommended daily intake for preterm infants.