Supplementation In Adolescents Research Articles

201 The effect of vitamin D and calcium supplementation in children and adolescents with cystic fibrosis and low bone mineral density

201 The effect of vitamin D and calcium supplementation in children and adolescents with cystic fibrosis and low bone mineral density

Effects of diet on behaviour and cognition in children

Diet can affect cognitive ability and behaviour in children and adolescents. Nutrient composition and meal pattern can exert immediate or long-term, beneficial or adverse effects. Beneficial effects mainly result from the correction of poor nutritional status. For example, thiamin treatment reverses aggressiveness in thiamin-deficient adolescents. Deleterious behavioural effects have been suggested; for example, sucrose and additives were once suspected to induce hyperactivity, but these effects have not been confirmed by rigorous investigations. In spite of potent biological mechanisms that protect brain activity from disruption, some cognitive functions appear sensitive to short-term variations of fuel (glucose) availability in certain brain areas. A glucose load, for example, acutely facilitates mental performance, particularly on demanding, long-duration tasks. The mechanism of this often described effect is not entirely clear. One aspect of diet that has elicited much research in young people is the intake/omission of breakfast. This has obvious relevance to school performance. While effects are inconsistent in well-nourished children, breakfast omission deteriorates mental performance in malnourished children. Even intelligence scores can be improved by micronutrient supplementation in children and adolescents with very poor dietary status. Overall, the literature suggests that good regular dietary habits are the best way to ensure optimal mental and behavioural performance at all times. Then, it remains controversial whether additional benefit can be gained from acute dietary manipulations. In contrast, children and adolescents with poor nutritional status are exposed to alterations of mental and/or behavioural functions that can be corrected, to a certain extent, by dietary measures.

Le rachitisme symptomatique de l’adolescent

Although systematic vitamin D supplementation in adolescents remains debated, rickets is nevertheless a well recognized pathology in this age group. Adolescence is an at-risk period because of rapid growth, insufficient calcium intake and/or vitamin D status. Surveys have shown that calcium intake is insufficient (< 1000 mg a day) in 45% of boys and 71% of girls and that vitamin D status is deficient (25-OH-D < 10 ng/ml). The aims of the study carried out by the Calcium Group of the Société Française de Pédiatrie, were to evaluate the frequency of rickets, and to define the criteria for the adolescent population at risk. Forty-one adolescents with rickets were hospitalized between 1985 and 2000. Most of the cases were from the Northern France: 20 from Paris and suburbs, eight from the North-West, four from the North, four from the North-East; five were from the Center of France. The mean age was 13 years and two months for the 28 girls, and 14 years and four months for the 13 boys. Eighty per cent of the adolescents were from immigrant families (33/41): 15 were from sub-Saharan Africa, ten from North Africa, six from Pakistan and two from Turkey. Two thirds of the adolescents were hospitalized in the 2nd quarter of the year. Some adolescents suffered from lower limb pain, 16 had deformations of lower limbs, particularly genu valgum, associated with pain; seven others had either muscle spasms (4), tetany (3). Serum calcium level was low (average 1.84 mmol/l: [1.1-2.5]), and serum 25-OH D level was extremely low. Radiographic characteristics observed were metaphyseal strips on the knees, with condensed edges at times, with the presence of bone demineralization. The treatment combined calcium and vitamin D, and was often administered intravenously when a hypocalcemia was detected. Rickets is not frequent in adolescents, but nonetheless this pathology is not exceptional, and the number of cases is probably under-estimated. Rickets affects immigrant adolescents in particular but nevertheless could also present a certain risk period for the general population.

Controlled trial of zinc supplementation in Chilean pregnant adolescents

Objective. The aim of this study was to analyze the effect of zinc supplementation on pregnancy outcome of Chilean adolescents from low socio-economic status (LSES); they often have low zinc intakes which may affect normal growth. Study design. A double blind randomised zinc supplementation trial was conducted with 804 healthy pregnant adolescents of LSES (age 16 ± 1.3 y.). Individuals were randomly assigned to Zn supplemented (S, n = 401) or Placebo (P, n = 403) groups. During the follow-up 297 were excluded. The S group received 20 mg Zn/d and the P group received a placebo, starting before 20 weeks of gestation. Results. On admission, both groups were comparable in age, rate of underweight, gestational age (12.5 vs 12.8 weeks), and dietary zinc intakes (7.3 vs 7.6 mg/d). At delivery, the S group presented a birthweight of 3,319 ± 460 g compared with 3,250 ± 514 g in the P group (NS). The proportion of low birthweight (<2,500 g) in the S group was significantly lower than in the P group (6/249 vs 16/258, p = 0.036). Prematurity rate was lower in S than P (14/249 vs 30/258, p = 0.016). Multiple regressions found a significant effect of maternal nutritional status (p = 0.011) and zinc supplementation (p = 0.05) on birthweight. No effects on pregnancy complications, RBC or plasma alkaline phosphatase were found. Conclusions. Oral zinc supplementation affects favourably the pregnancy outcomes in Chilean adolescents from low socio-economic status.

Dietary calcium, calcium supplementation, and blood pressure in African American adolescents

BackgroundIntake of calcium from the diet is inversely associated with blood pressure in observational studies and animal models but randomized trials in humans have found only small effects of calcium supplementation on blood pressure. A blood pressure-lowering effect of calcium supplementation may thus be restricted to persons with a low intake of calcium from the diet and specific genetic or other characteristics. Am J Clin Nutr 1998;68:648–55. ObjectiveA randomized trial was conducted to assess the effect of calcium supplementation on blood pressure in African American adolescents. Rapid growth during adolescence may increase calcium requirements, and avoidance of milk and milk products by some African Americans can result in low intake of calcium. DesignOne hundred sixteen adolescents (65 girls, 51 boys; mean age: 15.8 y) were given calcium (1.5 g/d) or placebo for 8 wk in a randomized, double-blind, crossover design. Blood pressure was measured after 2, 4, and 8 wk. Dietary calcium was determined with a validated food-frequency questionnaire. ResultsThe net effect (±SE) of calcium supplementation on diastolic blood pressure was a reduction of 1.9 ± 1.1 mm Hg (P = 0.04, one-tailed t test). Blood pressure reduction was greater in adolescents with lower intake of calcium from the diet (P = 0.003, one-tailed t test for interaction): -4.9 ± 1.6, -2.3 ± 1.6, and 1.4 ± 1.8 mm Hg for change in the lower (0.024-0.067 g Ca/MJ), middle (0.069-0.091 g Ca/MJ), and upper (0.093-0.217 g Ca/MJ) tertiles, respectively. No main effect on systolic blood pressure was detected. ConclusionThese findings suggest that calcium supplementation may lower diastolic blood pressure in African American adolescents with low dietary intakes of calcium.

Supplementation Trials with Calcium Citrate Malate: Evidence in Favor of Increasing the Calcium RDA During Childhood and Adolescence ,

The vast majority of peak adult bone mass is accumulated by the time longitudinal growth is complete. As peak bone mass is an important determinant of future fracture risk, the goal of the current calcium recommended dietary allowance during youth is to provide a calcium intake that allows individuals to reach their full genetic potential for acquiring skeletal mass. The advent of controlled trials of calcium supplementation and total body bone mass measurements in children and adolescents provide the first direct way of determining the amount of calcium necessary to achieve optimal skeletal accretion. These studies indicate that the current RDAs are insufficient to support optimal bone mass gain during growth and development. Based on the recent intervention trials, recommendations are made for an RDA of 1250 mg during childhood and 1450 mg during adolescence. These values are consistent with established calcium balance intake thresholds for growth during pre-adolescence and adolescence.

Effect of low sodium diet or potassium supplementation on adolescent blood pressure.

The roots of essential hypertension extend back into the first two decades of life, suggesting that effective intervention during those years may lead to a reduction in the incidence of adult hypertension. Decreasing the dietary sodium/potassium ratio offers a potentially effective approach to blood pressure reduction. This study tested the feasibility of 3-year sodium reduction or potassium supplementation in adolescents and the effect of these interventions on the rate of rise of blood pressure during adolescence. After 19,452 5th to 8th grade students were screened, 210 from the upper 15 percentiles of blood pressure distribution (105 boys, 105 girls) were randomly assigned to one of three groups: low sodium diet (70 mmol sodium intake per day), potassium chloride supplementation (normal diet plus 1 mmol/kg potassium chloride per day), or placebo (normal diet plus placebo capsule). Capsules for the potassium chloride and placebo groups were administered in a double blind protocol. Blood pressure was measured every 3 months for 3 years. The effect of the intervention was determined by comparing the rate of rise (slope) of blood pressure among the groups using a random-coefficient growth curve model. The boys groups and the girls placebo group had similar positive blood pressure slopes that were significantly different from zero. The girls low sodium group had a slightly negative slope (significantly lower than the slope of the girls placebo group), and the girls potassium group had a slightly positive slope. Both of these slopes were not significantly different from zero and were significantly lower than the slopes of the respective boys groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Schizotypal symptoms in patients with borderline personality disorders.

The authors assessed the frequency of schizotypal symptoms in 48 criteria-defined borderline patients. In the total sample schizotypal symptoms were surprisingly common; the average patient had more than seven symptoms and every patient at least one. Even in the "pure" DSM-III borderline subgroup, 67% of the patients had perceptual symptoms, 92% had cognitive symptoms, and 87% reported other "affective" symptoms. Visual phenomena were more prevalent than auditory ones, suggesting a possible contributing role for organic factors in borderline disorders. The results also indicate a close link between borderline and schizotypal personality disorders.

Mineral balance during nutritional supplementation in adolescents with Crohn disease and growth failure

The adaptive response of whole body mineral metabolism and collagen turnover to nutritional supplementation was determined in adolescent males with Crohn disease and growth failure. Body calcium, magnesium, phosphorus, and nitrogen status was characterized in six patients before and after 3 weeks of nutritional supplementation and in five healthy age- and sex-matched controls by the metabolic balance technique; collagen turnover was assessed by urinary hydroxyproline excretion. Fecal calcium (P less than 0.05), magnesium (P less than 0.01), and nitrogen (P less than 0.01) losses were significantly greater in the Crohn disease patients compared with the controls; after dietary supplementation, only fecal magnesium excretion increased further (P less than 0.001). Approximately twofold increases in phosphorus (P less than 0.001), nitrogen (P less than 0.02), and calcium (P less than 0.05) retention occurred with nutritional supplementation, whereas the marked renal conservation of phosphorus (P less than 0.001) suggested that this mineral was a limiting nutrient. Urinary hydroxyproline excretion was reduced (P less than 0.05) compared with the control values; however, with nutritional supplementation, urinary hydroxyproline excretion increased significantly (P less than 0.02), suggesting that the soluble fraction of tissue collagen was rapidly turning over during nutritional rehabilitation. These findings suggest that the mineral deficiencies present in adolescents with Crohn disease and growth failure can be reversed with nutritional supplementation. Furthermore, the improvement in nutritional status is reflected in the restoration of collagen-containing tissues of the body. However, nutrient imbalances may be present during nutritional therapy, thereby preventing optimal recovery from malnutrition.

Whole body leucine metabolism in adolescents with Crohn's disease and growth failure during nutritional supplementation

The adaptive response of whole body leucine metabolism to nutritional supplementation was determined in 6 adolescents with Crohn's disease and growth failure. Five healthy adolescents served as controls for body composition studies. In the first study period, all subjects received a constant diet comparable to usual intakes. In the second period, the patients were given overnight intragastric supplemental feedings that increased dietary protein and energy intakes approximately 40% (to 3.2 g/kg · day and 96 kcal/kg · day, respectively). During each dietary period, O2 consumption, nitrogen balance, whole body potassium (40K), and urinary creatinine measurements were obtained on all adolescents, and the patients received a primed, constant, intravenous infusion of [13C]leucine for 4 h in the fed state. Plasma leucine and expired carbon dioxide 13C-enrichments were determined by mass spectrometric techniques. In the first study, O2 consumption and nitrogen balances were similar between groups; in patients, 40K and urinary creatinine were reduced by 30% and 36%, respectively. With nutritional supplementation, nitrogen balance increased fourfold; O2 consumption and 40K increased by 32% and 10%, respectively. Similarly, whole body leucine flux increased from 166.9 ± 5.9 to 201.3 ± 11.2 μmol/kg · h (p < 0.05) due to a 66% increase in leucine incorporation into body protein (p < 0.01) and a 41% decrease in leucine oxidation (p < 0.05). Thus, these studies demonstrate that the mechanisms responsible for lean body mass accretion during nutritional supplementation in adolescents with Crohn's disease and growth failure are increased rates of amino acid incorporation into body protein (via protein synthesis] and decreased rates of amino acid oxidation.