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Biomedical subjects

S A Atkinson

Publications and source records attributed to S A Atkinson.

At least 37 records · Page 2Linked to original sources
PubMed1998

Moderate nutrient supplementation of mother's milk for preterm infants supports adequate bone mass and short-term growth: a randomized, controlled trial.

Our objectives were 1) to determine whether moderate nutrient supplementation of mother's milk (MM) for preterm infants, in the form of a new multinutrient fortifier (MNF), would improve short-term growth and bone mineral content (BMC) when compared with supplementation with calcium and phosphorus alone; and 2) to investigate whether moderate calcium and phosphorus intakes, in the form of calcium glycerophosphate (CaGP), resulted in a BMC similar to that of term corrected infants. Twenty-five preterm infants fed MM were randomly assigned to receive either MM+MNF or MM+CaGP. A third group of infants fed preterm formula (PTF) served as a comparison group. Whole-body BMC and lean and fat mass were determined by dual-energy X-ray absorptiometry (DXA) at full-term age. Nitrogen retention and calcium, phosphorus, and zinc intakes were determined by using mass balance techniques. Nitrogen retention was significantly lower in the MM+CaGP group than in the PTF group as were both weight and length gain (weight gain: 16.6 +/- 1.6, 14.2 +/- 2.0, and 16.1 +/- 2.9 g x kg(-1) x d(-1); length gain: 1.1 +/- 0.2, 0.9 +/- 0.2, and 1.1 +/- 0.3 cm/wk for the MM+MNF, MM+CaGP, and PTF groups, respectively). Biochemical indexes of mineral status and bone turnover were normal. Conservative amounts of calcium and phosphorus, as CaGP, resulted in adequate BMC. Moderate amounts of protein, calcium, and phosphorus plus trace elements added to MM in the form of an MNF resulted in improved linear growth but did not provide any advantages to BMC when compared with supplementation with calcium and phosphorus alone.

Anthropometry↗
PubMed1998

A qualitative and quantitative survey of forensic odontologists in England and Wales, 1994.

Forty forensic odontologists in England and Wales, as listed for the British Association for Forensic Odontology in Spring 1994, were surveyed by post. The 27 responses received, representing 67.5 per cent of those surveyed, were collated. The aims of the survey were to establish the distribution of experience between those forensic odontologists; to confirm the geographic areas covered by them; to establish the most likely source of introduction to forensic work; to ascertain the proportion of work involving court appearances; to establish a pattern of trends or common risk factors, if any, of susceptibility towards bitemark injury in respect of motive, age, gender, race, socioeconomic factors, and family background in relation to child abuse and adult sexual assault; and to establish if there are preferential sites for bitemark injury according to motive. The survey concluded that most of the work is almost exclusively conducted by a few forensic odontologists, with little or no experience gained for the majority of those available.

Adolescent↗
PubMed1998

Dexamethasone-induced abnormalities in growth and bone metabolism in piglets are partially attenuated by growth hormone with no synergistic effect of insulin-like growth factor-I.

Dexamethasone (DEX) therapy improves pulmonary compliance in premature infants with chronic lung disease; however, normal growth and bone development are impaired. Because DEX may mediate its effects by altering the GH-IGF-I axis, we investigated whether adjunctive therapy with GH or GH + IGF-I during DEX therapy could attenuate these DEX-induced effects. Piglets were randomized to placebo, oral tapered DEX (0.5, 0.3, and 0.2 mg kg(-1) d(-1) over 14 d), DEX + GH (0.1 mg kg(-1) d(-1)) or DEX + GH + IGF-I (0.1 mg kg(-1) d(-1)). Final whole body weight and length were improved with GH or GH + IGF-I compared with the DEX alone group. Plasma GH and IGF-I were not influenced by DEX, but infusion of IGF-I resulted in higher (p < 0.05) plasma IGF-I compared with all other groups at d 15. DEX reduced (p < 0.05) circulating IGFBP-2 and IGFBP-3 and liver IGFBP-2 and IGFBP-4 mRNA expression compared with controls. Treatment with DEX alone resulted in lower (p < 0.05) plasma osteocalcin, urinary N-telopeptide, and whole body and femur bone mineral density compared with controls, whereas results with piglets receiving adjunctive GH or GH + IGF-I were similar to those of controls. Given adjunctively, GH alone appears to partially counter the abnormalities in growth and bone metabolism associated with DEX therapy; however, this improvement cannot be attributed to higher circulating IGF-I, because combined therapy did not further improve growth or bone homeostasis compared with DEX + GH treatment. Growth hormone therapy has the potential to stimulate growth in infants exposed to steroid treatment.

Animals↗
PubMed1998

Tamoxifen attenuates the effects of exogenous glucocorticoid on bone formation and growth in piglets.

Tamoxifen (Tam) has been shown to inhibit dexamethasone (Dex)-mediated effects on bone formation in vitro. Our objective was to determine whether Tam would block Dex-induced osteopenia and growth inhibition in growing piglets. Four-day-old male Yorkshire piglets were adapted to a liquid formula diet (400 ml/kg x day) and randomized to one of four groups (n = 5/group): Dex (0.5 mg/kg x day), Tam (1 mg/kg x day), Dex plus Tam, or placebo control (vehicle only). Both drugs were administered by orogastric gavage twice daily for 12 days. At baseline and at the end of treatment, whole body bone mineral density (BMD) was determined by dual energy x-ray absorptiometry (Hologic QDR1000W). Plasma osteocalcin and PTH were measured on days 0 and 12, and urinary N-telopeptide was measured on day 12. Changes in axial length and daily weight were also measured. Delta whole body BMD was 29% lower (P < 0.05) in Dex alone treated piglets than in controls (0.033 vs. 0.047 g/cm2, respectively), whereas the maximum change in BMD in Dex plus Tam group (0.046 g/cm2) was similar to that in controls. Concurrent Tam administration reduced the Dex-induced deficit in weight gain by 56% (P < 0.05) and the deficit in axial length gain by 72% (P < 0.01). In Dex alone treated piglets, PTH was significantly elevated (7-fold), whereas osteocalcin and N-telopeptide were significantly reduced compared with control values. These effects were prevented by Tam. These data suggest that the suppression of growth and other changes in parameters of bone metabolism induced by glucocorticoids in vivo can be attenuated by Tam.

Animals↗
PubMed1998

Bone and mineral abnormalities in childhood acute lymphoblastic leukemia: influence of disease, drugs and nutrition.

In children with acute lymphoblastic leukemia (ALL), abnormalities in mineral homeostasis and bone mass were first reported by our group in the late 1980s. Prospective longitudinal cohort studies in 40 consecutive patients receiving treatment according to the Dana-Farber Cancer Institute (DFCI) protocol 87-001 and 16 children receiving DFCI protocol 91-001 afforded us the opportunity to explore various etiologies of the observed abnormalities in mineral and bone metabolism, specifically the leukemic disease process and chemotherapeutic drugs such as steroids and aminoglycoside antibiotics. At diagnosis of ALL, > 70% of children had abnormally low plasma 1,25-dihydroxyvitamin D, 73% had low osteocalcin and 64% had hypercalciuria, indicating an effect of the leukemic process on vitamin D metabolism and bone turnover. During remission induction, treatment with high-dose steroid (prednisone or dexamethasone) resulted in further reduction in plasma osteocalcin and elevated parathyroid hormone levels. During 24 months of chemotherapy-maintained remission, reduction in bone mineral content (BMC), as measured by Z-scores, occurred in 64% of children, most severely affecting those > 11 years of age. A reduction in BMC during the first 6 months had a positive predictive value of 64% for subsequent fracture. By the end of 2 years of therapy, fractures occurred in 39% of children and radiographic evidence of osteopenia was found in 83% of the entire study group. Investigations of the biochemical basis of the bone abnormalities revealed that by 6 months hypomagnesemia developed in 84% of children (of whom 52% were hypermagnesuric) and plasma 1,25-dihydroxyvitamin D remained abnormally low in 70%. Altered magnesium status was attributed to renal wastage of magnesium following cyclical prednisone therapy and treatment with aminoglycoside antibiotics such as amikacin for fever accompanying neutropenia. Dietary intake and absorption of magnesium were normal. In 10 children treated for hypomagnesemia with supplemental magnesium for up to 16-20 weeks, plasma magnesium normalized in only 50% of subjects.

Adolescent↗
PubMed1998

Growth and body composition in response to chemotherapy in children with acute lymphoblastic leukemia.

Severely malnourished children afflicted by acute lymphoblastic leukemia (ALL), particularly in developing countries, have reduced tolerance to chemotherapy and a compromised prospect for survival. We investigated the prevalence and severity of alterations in growth and nutritional status in children with ALL from population-based referral areas in Canada. All children were treated with Dana-Farber Cancer Institute ALL Consortium protocols. First, the relative impact of cranial irradiation (CI) and chemotherapy on growth was studied in 116 children at diagnosis and at 6-month intervals during treatment. We observed a decline in height standard deviation (SD) score in the first year in all children, and a further decline in height SD score during the second year only in the children who received CI. Weight reduction occurred in the first year, but during the second year there was a disproportionate increase in weight compared with height, suggesting that children treated with ALL have a tendency toward obesity. Both chemotherapy and CI contribute to the altered growth observed in children treated for ALL. Second, intestinal functional integrity was assessed in 16 children during post-induction chemotherapy. Nutrient intake was adequate and there was minimal evidence of malabsorption: fat malabsorption occurred in only 1 child (after treatment-related pancreatitis), abnormal D-xylose absorption occurred in 2 children at 6 months of therapy (returning to normal 6 months later) and abnormal lactose absorption occurred in 4 children. Third, weight, height, whole body lean and fat mass measured by dual-energy X-ray absorptiometry and serum albumin were determined at diagnosis and at 6-month intervals throughout therapy in 19 children with ALL. Height SD scores decreased significantly during treatment. Serum albumin was abnormally low in 6/19 at diagnosis and 14/18 during intensive consolidation therapy. The mean change in the ratio of lean mass to total body weight showed a 5% reduction by 6 months of therapy. Body fat increased from a mean of 22% at diagnosis to 28% at completion of therapy. The majority of children treated for ALL thus have significant changes in nutritional status manifested by reductions in growth, alterations in lean and fat body mass and abnormally low serum proteins during intensive therapy.

Antineoplastic Agents↗
PubMed1997

Longitudinal assessment of growth and bone mineral accretion in prematurely born infants treated for chronic lung disease with dexamethasone.

The objective of this study in premature infants was to assess the relationship between dexamethasone, growth and bone mineral accretion. Nine appropriate size for gestational age premature infants treated for chronic lung disease with tapering doses of dexamethasone (0.5-0.1 mg/kg/day over 37 +/- 7 days) were individually matched to a comparison infant by sex, gestational age, birth-weight, and type of feed. Infant growth and bone mineral accretion were measured at equivalent gestational ages from recruitment until 6 months corrected age. During hospitalization, mean rate of weight, length and head circumference growth and bone mineral accretion in the distal radius were significantly lower in the dexamethasone-treated infants in spite of similar nutrient intakes. Dexamethasone infants had significantly lower plasma phosphorus, and urinary calcium, pyridinoline and N-telopeptide excretion. Dexamethasone affected absolute length, but not weight, throughout the study. No significant differences were observed in body composition or absolute radial and whole body bone mineral content. The results indicate that dexamethasone therapy compromises growth and bone mineral accretion in small premature infants. 'Catch-up' linear growth was not evident at 6 months of age and reflects the importance of early nutrition interventions.

Amino Acids↗
PubMed1997

Whole body lean mass is altered by dexamethasone treatment through reductions in protein and energy utilization in piglets.

The objective of this study was to assess the effect of dexamethasone on growth, body composition and protein metabolism using the piglet as a model for rapidly growing premature infants. Seven-day-old male pigs (n = 18) were randomized to 0.5 mg/kg/day oral dexamethasone or placebo for 15 consecutive days. Weight and length gains and weight gained per energy or protein consumed were significantly lower in the dexamethasone group. Serum urea nitrogen was significantly higher in the dexamethasone group by day 15 of the study. No differences were observed between groups for urinary creatinine. The whole body percent lean mass was significantly lower and percent fat mass was significantly higher in the dexamethasone piglets, as measured by dual energy X-ray absorptiometry. In young piglets, dexamethasone, at doses similar to those in premature infants, induces protein catabolism, impairs growth and alters its composition.

Absorptiometry, Photon↗
PubMed1997

Improvement in the accuracy of dual energy x-ray absorptiometry for whole body and regional analysis of body composition: validation using piglets and methodologic considerations in infants.

Previously, we conducted dual energy x-ray absorptiometry (DXA) (Hologic QDR-1000/W) scans and carcass analysis of piglets to evaluate the Pediatric Whole Body software (PedWB) (V5.35) for use in infants. A software upgrade designed for infant whole body (InfWB) (V5.56) led to a reassessment of DXA by: 1) reanalysis of the original scans using InfWB software and 2) comparison of InfWB-estimates of bone mineral content (BMC) and lean and fat mass with chemical analysis. Other assessments included 1) methods of regional analysis and 2) artifacts and the Infant Table Pad in the scan field. The mean coefficients of variation for InfWB whole body measures in small piglets (n = 10, weight 1575 +/- 73 g) and large piglets (n = 10, weight 5894 +/- 208 g) were less than 2.6% except for fat mass which was higher (8.0% versus 6.3% and 6.6% versus 3.5%, respectively) compared with PedWB. In large piglets InfWB produced good estimates of BMC, lean and fat masses. In small piglets, fat mass by InfWB was correlated with chemical analysis, but not by PedWB. There was improvement in the estimation of BMC with InfWB, from 27 +/- 2.2 g to 32 +/- 2.3 g (carcass ash = 38 +/- 3.3 g). Femur BMC analysis by InfWB was precise and was accurate when compared with chemical analysis. Artifacts in the DXA scan field (diapers and blankets) resulted in an increase of the DXA-estimated fat and lean masses. The Infant Table Pad increased the estimate of fat mass in a small piglet by 50%, thus further study is required before it is used routinely. Improvements of the DXA technology have resulted in a more accurate tool, if scanning procedures are carefully implemented.

Absorptiometry, Photon↗
PubMed1996

Altered mineral metabolism and bone mass in children during treatment for acute lymphoblastic leukemia.

Children with acute lymphoblastic leukemia (ALL) often develop bone pain, abnormal gait, and unusual fractures while in remission and receiving continuing chemotherapy. A prospective longitudinal cohort study was undertaken of bone mass and biochemical mineral status in 40 consecutive children (27 male, 13 female, aged 0.3-17.0 years) receiving therapy on the Dana-Farber Cancer Institute protocol 87-01. Radiography, lumbar spine dual-photon absorptiometry, and biochemical measurements of mineral status were performed at diagnosis and at 6-month intervals throughout 24 months of chemotherapy. Eleven patients were not completely evaluated (4 deaths and 7 off study). Radiographic evidence of osteopenia was observed in 10, 64, and 76% at diagnosis, 12 and 24 months, respectively. Fractures occurred in 39% of children during treatment. Reduction in bone mineral content (BMC), as measured by Z scores, occurred in 64% of patients and was most severe in those greater than 11 years of age at diagnosis. Reduction in BMC during the first 6 months of therapy had a positive predictive value of 64%, while an increase in BMC had a negative predictive value of 82% for subsequent fracture. By 6 months of therapy, 31/37 (84%) children were hypomagnesemic, of whom 16 (52%) were hypermagnesuric. Plasma osteocalcin was subnormal at diagnosis in 29/40 (73%) but increased to normal by 6 months of treatment. Vitamin D status was normal throughout, but plasma 1,25-dihydroxyvitamin D remained subnormal in greater than 70% of children. Urinary cross-link N-telopeptide was normal at diagnosis and became elevated in 58% of children by the end of therapy. Suppressed bone mineralization is evident at diagnosis in a minority of children with ALL. Skeletal morbidity and a reduction in bone mineral mass become more prevalent during treatment, with increased bone resorption, perhaps mainly as a consequence of corticosteroid administration.

Adolescent↗
PubMed1996

Hypermagnesiuria and hypercalciuria in childhood leukemia: an effect of amikacin therapy.

PURPOSE: The purpose of this study is to assess the effects of amikacin on renal proximal tubular function, and on magnesium (Mg) and calcium (Ca) status in children treated for acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: Eighteen children (11 male/7 female, ages 2-18 years) receiving antileukemic therapy (Dana Farber Cancer Institute protocols 87-001 or 91-001) and admitted for febrile neutropenia to The Children's Hospital at Chedoke-McMaster, Hamilton, Ontario were recruited into this descriptive prospective study. Each child was treated with amikacin (7.5 mg/kg/12 h x 10-14 days) for one or more courses. RESULTS: No patient demonstrated elevations in amikacin trough levels. beta 2-Microglobulinuria, glucosuria, proteinuria, and hyperphosphaturia were absent. Children (50% presenting with hypomagnesemia (< 0.77 mmol/L) had a significant rise in mean urinary Mg:creatinine (0.46 +/- 0.27 versus 0.82 +/- 0.38 mmol, mean +/- SD, p < 0.05) in response to amikacin therapy and the mean Ca:creatinine ratio increased by 95% after 10-14 days of amikacin treatment. Serum Mg and Ca did not change notably after treatment, irrespective of initial Mg status. CONCLUSIONS: Aminoglycoside therapy in children with ALL is not associated with overt nephrotoxicity. A transient renal leak of Mg and Ca does occur. Screening of ALL children for mild hypomagnesemia may help to identify those most at risk of disruption of renal conservation of Mg and possibly Ca.

Adolescent↗
PubMed1996

Mixed carbohydrate supplementation increases carbohydrate oxidation and endurance exercise performance and attenuates potassium accumulation.

We studied the effects of different CHO supplements on exercise metabolism (1 hr at 75% VO2max) and performance (fatigue time at 85% VO2max) in 8 male endurance athletes (VO2max = 68.8 +/- 3.8 ml.kg-1.min-1. Four treatments were administered in a randomized, double-blind fashion: Trial A = 3-day pretest, postexercise supplementation (177 kcal [81% carbohydrate, 19% protein] consumed < 10 min after exercise) + 600 ml 8% glucose polymers/ fructose 1 hr pretesting + 600 ml 8% glucose polymers/glucose during testing; Trial B = placebo during 3-day pretest + remainder same as Trial A; Trial C = placebo at all time points; and Trial D = same as Trial B with 8% glucose 1 hr before the test as well as during the test. Time to fatigue at 85% VO2max (increases 24%) and total CHO oxidation were greater for A versus C (p < .05). Plasma glucose concentration was higher for A and B versus C, while increases in plasma potassium concentration were attenuated for A versus C (both p < .05). None of the supplements had differential effects upon hematocrit, plasma sodium [Na+] and lactate, VO2, or rating of perceived exertion during exercise. Three-day preexercise protein + carbohydrate supplements followed by 1-hr pre- and during-exercise mixed carbohydrate supplements increased time to fatigue and carbohydrate oxidation and attenuated rises in plasma [K+] compared to placebo.

Adult↗
PubMed1995

Mineral homeostasis and bone mass at diagnosis in children with acute lymphoblastic leukemia.

OBJECTIVE: To determine whether the osteopenia and unusual fractures observed in children with acute lymphoblastic leukemia (ALL) were related to the disease rather than to its treatment. DESIGN: Prospective analysis of the bone and mineral status in 40 consecutive children with ALL seen in a pediatric tertiary-care referral center. METHODS: Biochemical indicators of mineral, endocrine, and vitamin D status were measured before initiation of therapy. Bone mass was determined radiographically and by dual-photon absorptiometry of the lumbar region of the spine (L2-L4). Correlations between clinical observations, leukemia variables, bone mass, and biochemical assessment were determined. RESULTS: At the time of diagnosis musculoskeletal pain was present in 36% of patients and was more common in children with CD10-positive leukemia and leukocyte counts less than 20 x 10(9) cells/L. Radiographic evidence of osteopenia and fractures was observed in 13% and 10% of children, respectively. The mean bone mineral content was normal. Bone mass measurement z scores correlated with plasma 1,25-dihydroxyvitamin D3 concentrations (r = 0.43, p < 0.05). Plasma calcium, magnesium, phosphorus, and 25-hydroxyvitamin D3 levels were normal. Low plasma osteocalcin (mean +/- SD, 1.6 +/- 1.6 nmol/L) and 1,25-dihydroxyvitamin D3 (33.4 +/- 26.4 pmol/L) values were observed. Parathyroid hormone levels were low in 14% of children. Hypercalciuria was detected in 64% of children. Urinary deoxypyridinoline was lower (p < 0.01) than in age-matched control subjects. Histomorphometric measurements of iliac bone showed abnormalities in mineralization in the biopsy specimens from three of nine children. CONCLUSION: Most children with ALL have alterations in bone metabolism and bone mass when first examined. These data suggest defective mineralization as the mechanism for decreased bone mass and implicate the leukemic process as causative.

Adolescent↗
PubMed1995

Dexamethasone treatment impairs calcium regulation and reduces bone mineralization in infant pigs.

Calcium and vitamin D metabolism, bone mineralization, and growth were studied in piglets randomly assigned to 15 d of dexamethasone (0.5 mg.kg-1.d-1, orally) or placebo. Growth velocity was significantly reduced by dexamethasone treatment (P < 0.001). Pigs in the dexamethasone group demonstrated lower 45Ca absorption by in situ intestinal perfusion (P < 0.01). Plasma 25-hydroxycholecalciferol (calcidiol) and 1,25-dihydroxycholecalciferol (calcitriol) were lower (P < 0.05) and the urinary ratio of calcium to creatinine was higher (P < 0.05) after 15 d of dexamethasone compared with placebo. Differences between pre- and postosteocalcin (P < 0.01) and pyridinoline (P < 0.01) were higher and wholebody, lumbar, and femur bone mineral density were lower (P < 0.05) in dexamethasone-treated piglets. Dexamethasone-induced reductions in bone mineral mass likely result from reduced vitamin D status, reduced intestinal calcium absorption, elevated urinary calcium loss and direct effects of the steroid on bone. When dexamethasone is used in premature infants to improve lung function, negative effects on growth and bone metabolism could occur.

Animals↗
PubMed1995

Carbohydrate loading and metabolism during exercise in men and women.

During endurance exercise at approximately 65% maximal O2 consumption, women oxidize more lipids, and therefore decrease carbohydrate and protein oxidation, compared with men (L.J. Tarnopolsky, M.A. Tarnopolsky, S.A. Atkinson, and J.D. MacDougall. J. Appl. Physiol. 68: 302-308, 1990; S.M. Phillips, S.A. Atkinson, M.A. Tarnopolsky, and J.D. MacDougall. J. Appl. Physiol. 75: 2134-2141, 1993). The main purpose of this study was to examine the ability of similarly trained male (n = 7) and female (n = 8) endurance athletes to increase muscle glycogen concentrations in response to an increase in dietary carbohydrate from 55-60 to 75% of energy intake for a period of 4 days (carbohydrate loading). In addition, we sought to examine whether gender differences existed in metabolism during submaximal endurance cycling at 75% peak O2 consumption (VO2 peak) for 60 min. The men increased muscle glycogen concentration by 41% in response to the dietary manipulation and had a corresponding increase in performance time during an 85% VO2 peak trial (45%), whereas the women did not increase glycogen concentration (0%) or performance time (5%). The women oxidized significantly more lipid and less carbohydrate and protein compared with the men during exercise at 75% VO2-peak. We conclude that women did not increase muscle glycogen in response to the 4-day regimen of carbohydrate loading described. In addition, these data support previous observations of greater lipid and lower carbohydrate and protein oxidation by women vs. men during submaximal endurance exercise.

Adult↗
PubMed1993

Validation and application of dual-energy x-ray absorptiometry to measure bone mass and body composition in small infants.

Precision and validity of dual-energy x-ray absorptiometry (DXA) for analysis of whole-body composition in infants were assessed by 1) scanning piglets in triplicate to calculate CVs, and 2) comparing DXA estimates with chemical analysis of whole carcass. The mean CVs for all DXA measures in small piglets and large piglets were < 2.5%, except for fat mass, which were 6.3% and 3.5%, respectively. In large piglets DXA provided reasonable estimates of chemical analysis for bone mineral content (BMC), lean body mass, and fat mass, but only for lean body mass in small piglets. DXA overestimated fat by twofold and underestimated BMC by a third in small piglets. Scans of prematurely born infants (n = 17) at term and at 3, 6, and 12 mo corrected age demonstrated that changes in BMC, lean body mass, and fat mass can be quantitated by DXA. However, further refinement of DXA technology is necessary before reliable measures of BMC and fat mass in small infants are attainable.

Absorptiometry, Photon↗
PubMed1993

A multi-element isotopic tracer assessment of true fractional absorption of minerals from formula with additives of calcium, phosphorus, zinc, copper and iron in young piglets.

True fractional absorption of minerals was measured to determine the bioavailability of Zn, Fe, Mn and Se from liquid formulas fortified with stepwise additions of Ca and P (as Ca glycerophosphate and carbonate, Ca*P), and Zn, Cu and Fe (as sulfate salts). Growth, deposition of tracers in organs and bone mineral content of femurs as assessed by single photon absorptiometry were measured. Four-day-old piglets (n = 36) were randomly assigned to groups fed a basal diet or additions of Ca*P (Ca = 25, P = 18 g/kg dry diet), Ca*P+Zn (Zn = 0.04 g/kg), Ca*P+Zn+Cu (Cu = 0.007 g/kg) or Ca*P+Zn+Cu+Fe (Fe = 0.008 g/kg). Oral and intravenous administration of extrinsic isotopes of 59Fe, 54Mn, 65Zn, 75Se and 47Ca was followed by fecal monitoring for 15 d and true absorption calculated after accounting for endogenous excretion. Addition of Ca*P+Zn reduced Zn absorption (P < 0.05) and Ca*P+Zn+Cu reduced Fe absorption (P < 0.01), but Mn and Se absorptions were not altered. Uptake of only Zn tracer into heart was significantly different (P < 0.05) among diet groups. Weight gain and linear growth were similar in all groups. Addition of Ca*P produced higher bone mineral density, but its effect on Zn absorption warrants further investigation.

Absorptiometry, Photon↗