Adequate calcium intake during long periods improves bone mineral density in healthy children : data from the Childhood Obesity Project

Background: Bone mineralization can be influenced by genetic factors, hormonal status, nutrition, physical activity and body composition. The association of higher calcium (Ca) intake or Ca supplementation with better bone mineral density (BMD) remains controversial. Furthermore, it has been speculated that maintaining long-term adequate Ca intake rather than having a brief supplementation period is more effective. The aim of the study was to prospectively analyse the influence of adequate Ca intake on BMD at 7 years of age in European children. Methods: Data from the Childhood Obesity Project were analysed in a prospective longitudinal cohort trial. Dietary intake was recorded using 3-day food records at 4, 5 and 6 years of age. The probability of adequate intake (PA) of Ca was calculated following the American Institute of Medicine guidelines for individual assessments, with FAO, WHO and United Nations University joint expert consultation dietary recommendations. Children were categorised as having high Ca PA (PA >95%) or not (PA <95%). At 7 years, whole body (WB) and lumbar spine (LS) BMD were measured in the Spanish subsample by dual-energy x-ray absorptiometry. Internal BMD z-scores were calculated; BMD below 121 z-score were considered to indicate osteopenia, and BMD z-scores below 122, \u201clow bone mineral density for age\u201d. Results: BMD was measured in 179 children. Ca intake at 6 years was positively correlated with LS BMD at 7 years (R = 0.205, p = 0.030). A Ca increase of 100 mg/day explained 19.4% (p = 0.011) of the LS BMD z-score variation, modifying it by 0.089 (0.021, 0.157) units. Children with Ca PA >95% at 5 and 6 or from 4 to 6 years of age showed higher BMD z-scores at the LS and WB levels than children with Ca PA <95% (p < 0.001 and p < 0.05 for LS and WB BMD, respectively). Ca PA >95% maintained over 2 years explained 26.3% of the LS BMD z-score variation (p < 0.001), increasing it by 0.669 (0.202, 1.137). PA >95% maintained over 3 years explained 24.9% of the LS BMD z-score variation, increasing it by 0.773 (0.282, 1.264). The effects of Ca adequacy on WB BMD were similar. Children with PA >95% over 2 years had an Odds ratio of 13.84 and 12 for osteopenia at the LS and WB levels, respectively (p = 0.001). Conclusions: Long periods of adequate Ca intake in childhood increase BMD and reduce osteopenia risk. The Childhood Obesity Project clinical trial (CHOP) was registered at clinicaltrials.gov as NCT00338689

Micronutrient intake adequacy in children from birth to 8 years : data from the Childhood Obesity Project

Background: In European countries, suboptimal intake has been reported for several micronutrients (as calcium, iron, zinc, vitamin B12, D and folate) in both adulthood and childhood. No studies to date have prospectively compiled nutrient intake from healthy children in different European countries using the same methodology. Aim: To describe the adequacy of micronutrient intake during the first eight years of life in children from 5 European countries. Methods: Prospective observational trial analyzing data from the EU Childhood Obesity Project. Infants were enrolled within the first two months of life and were followed regularly to age 8 years. Dietary intake was collected periodically with 3-day food records. Nutrient intake adequacy was estimated for calcium, phosphorus, iron, zinc, magnesium, iodine, folate and vitamins B12, A and D, following the American Institute of Medicine (IOM) guidelines at group (prevalence of adequacy >80%) and individual (high probability of adequate intake >80% of the children) level; the assessment was based on the Estimated Average Requirements of nutrients of the FAO, WHO and United Nations University (FAO/WHO/UNU) or the IOM if FAO/WHO/UNU data were not available. Results: Intake data were available for a decreasing number of children, from 904 at 3 months to 396 at 8 years. Iron, iodine, folate and vitamin D were inadequately consumed when assessing adequacy at group level; at individual-level less than 80% of the children showed high probability of adequate intake for iron, iodine, folate and zinc at all ages, and calcium from 12 months onwards. Conclusions: Accurate dietary intake and adequacy assessment methodology in this prospective cohort of European children found iron, calcium, vitamin D, folate, iodine and zinc to be inadequately consumed in childhood, as described previously by epidemiologic studies. Further studies are needed to elucidate health consequences of these deficiencies. CHOP trial was registered at clinicaltrials.gov as NCT00338689