Allowance For Adults Research Articles

Metabolic bone disease in HIV infection

HIV mainly replicates in CD4þ T lymphocytes andmonocyte/macrophages causing severe immunologicalimpairment. In addition to the immune system, HIVinfection affects tissues and organs such as kidney, liver,the central nervous system, heart and bone showing acomplex pathogenesis [1].The advent and widespread use of highly activeantiretroviral therapy (HAART) in the last two decadeshasled toa markedimprovementinthe treatmentofHIVdisease even though viral infection cannot be eradicatedbecause HAART does not completely eliminate the viralreservoirs [2]. HAART has dramatically changed thecourseofHIVinfection froma fatalinfectiontoachronicand relatively manageable disease. The increased lifeexpectancyofHIVpatientsandtheeffectsofHAARThavechanged the management of HIV infection. Nowadaysmedical treatment is no longer focused solely on HIVinfection, opportunistic diseases and monitoring immunederangement, but also includes the control of metabolic,cardiovascular, liver, bone and kidney complications. Inparticular, bone alterations have been observed in thecourse of HIV disease representing a pivotal clinicalprobleminthemanagementofHIVpatientsespeciallyforapossible development of bone fractures [3]. The majorbonelesionsdetectableinHIVpatientsarerelatedtobonedemineralization (osteopenia/osteoporosis and osteoma-lacia) and osteonecrosis ([4] for a review).This report will discuss the pathogenesis, diagnosis andtreatment of major bone complications represented bybone demineralization diseases during HIV infection andHAART treatment.

Effect of osmotic dehydration on the stabilization of calcium-fortified apple slices (var. Granny Smith): Influence of operating variables on process kinetics and compositional changes

Commonly available calcium-fortified foods include non-structured and formulated foods. In contrast, vacuum impregnation allows the introduction of physiologically active compounds to vegetal tissues without disrupting their cellular structure, but inducing changes in their behaviour during further processing. In the particular case of osmotic dehydration of apple slices (var. Granny Smith) with a 55 Brix sucrose solution, both the water loss and the gain in soluble solids were observed to be affected by the amount of calcium incorporated into their porous structure by means of vacuum impregnation, the processing temperature and the addition of 1% of calcium lactate to the osmotic solution. To be precise, water removal was observed to decrease as the calcium content of the vacuum impregnated samples increased from 0% to 40% of the recommended daily allowances for adults in a 200 g sample. Overall, the addition of 1% calcium lactate to the osmotic solution decreased the constant rate of both water loss and gain in soluble solids, but resulted in a final product with an increased mineral content. However, an increase in the temperature of the osmotic solution from 30 to 50 °C was reported to promote faster water loss and soluble solids uptake, but to a different extent depending on the fortification level required for the processed samples. Despite the loss of part of the calcium incorporated to apple slices by means of vacuum impregnation, osmotic dehydration can be considered as a useful tool to increase the stability of this kind of product without seriously reducing its nutritional value.

Zinc toxicology following particulate inhalation

The current mini-review describes the toxic effects of zinc inhalation principally in the workplace and associated complications with breathing and respiration. The International Classification of Functioning, Disability and Health Criteria were used to specifically select articles. Most of the commercial production of zinc involves the galvanizing of iron and the manufacture of brass. The recommended daily allowance for adults is 15 mg zinc/day. Metal fume fever associated with inhalation of fumes of ZnO is characterized by fatigue, chills, fever, myalgias, cough, dyspnea, leukocytosis, thirst, metallic taste and salivation. ZnCl2 inhalation results in edema in the alveolar surface and the protein therein the lavage fluid is elevated. Particular pathological changes associated with zinc intoxication include: pale mucous membranes; jaundice; numerous Heinz bodies; and marked anemia. Adequate ambient air monitors for permissible exposure limits, excellent ventilation and extraction systems, and approved respirators are all important in providing adequate protection.

Effectiveness of selenium supplements in a low-selenium area of China

Selenium is an essential micronutrient with a recommended dietary allowance for adults of 55 mug/d. It functions as an essential constituent of selenoproteins. Although there is no evidence of selenium deficiency in the United States, people in many other areas of the world are selenium deficient, with the consequence that they are unable to express their selenoproteins fully. We carried out a supplementation trial in a selenium-deficient population in China to assess the requirement for selenium as selenite and as selenomethionine. One hundred twenty subjects with an average selenium intake of 10 mug/d were randomly assigned and administered tablets containing no selenium or amounts as high as 66 mug Se/d for 20 wk. Plasma was sampled before supplementation and at 4-wk intervals during supplementation and was assayed for the 2 plasma selenoproteins, glutathione peroxidase and selenoprotein P. Full expression of glutathione peroxidase was achieved with 37 mug Se/d as selenomethionine and with 66 mug/d as selenite. Full expression of selenoprotein P was not achieved at the highest doses of either form. Full expression of selenoprotein P requires a greater selenium intake than does full expression of plasma glutathione peroxidase. This suggests that selenoprotein P is a better indicator of selenium nutritional status than is glutathione peroxidase and that the recommended dietary allowance of selenium, which was set with the use of glutathione peroxidase as the index of selenium status, should be revised. Selenium as selenomethionine had nearly twice the bioavailability of selenium as selenite.

Zinc.

The use of zinc in metal alloys and medicinal lotions dates back before the time of Christ. Currently, most of the commercial production of zinc involves the galvanizing of iron and the manufacture of brass. Some studies support the use of zinc gluconate lozenges to treat the common cold, but there are insufficient data at this time to recommend the routine use of these lozenges. Zinc is an essential co-factor in a variety of cellular processes including DNA synthesis, behavioral responses, reproduction, bone formation, growth, and wound healing. Zinc is a relatively common metal with an average concentration of 50 mg/kg soil and a range of 10-300 mg/kg soil. Meat, seafood, dairy products, nuts, legumes, and whole grains contain relatively high concentrations of zinc. The mobility of zinc in anaerobic environments is poor and therefore severe zinc contamination occurs primarily near points sources of zinc release. The recommended daily allowance for adults is 15 mg zinc. The ingestion of 1-2 g zinc sulfate produces emesis. Zinc compounds can produce irritation and corrosion of the gastrointestinal tract, along with acute renal tubular necrosis and interstitial nephritis. Inhalation of high concentrations of zinc chloride from smoke bombs detonated in closed spaces may cause chemical pneumonitis and adult respiratory distress syndrome. In the occupational setting inhalation of fumes from zinc oxide is the most common cause of metal fume fever (fatigue, chills, fever, myalgias, cough, dyspnea, leukocytosis, thirst, metallic taste, salivation). Zinc compounds are not suspected carcinogens. Treatment of zinc toxicity is supportive. Calcium disodium ethylenediaminetetraacetate (CaNa2EDTA) is the chelator of choice based on case reports that demonstrate normalization of zinc concentrations, but there are few clinical data to confirm the efficacy of this agent.

Nutritional vitamin B 12 deficiency and folate deficiency in an adolescent patient presenting with anemia, weight loss, and poor school performance

Vitamin B/12 is an essential vitamin for hematopoiesis and neurologic and psychiatric health. Because it is not synthesized in the human body it must be supplied exogenously in the diet. Deficiency of cobalamin is rare and usually results from malabsorption. Other rare causes include the use of nitrous oxide transcobalamin deficiency and inadequate dietary intake. Vitamin B/12 is primarily found in meat and dairy products. The recommended dietary allowance for adults is 2-4 µg/day; however most adults consume approximately 1-2 mg/day. Because the body also stores approximately 4-5 mg of vitamin B/12 predominantly in the liver it takes 3-6 years before dietary vitamin B/12 deficiency may become clinically evident. Of the few reported adult and neonatal cases of symptomatic deficiency secondary to inadequate dietary intake vegetarian diets are usually implicated although cobalamin deficiency has also been associated with nonvegetarian diets. (excerpt)

Role of Glycemic Control and Protein Restriction in Clinical Management of Diabetic Kidney Disease

To assess the role of control of blood glucose levels and restriction of dietary protein in the management of diabetic nephropathy. We summarize the results of pertinent published studies of glycemic control and modification of protein intake to provide information about strategies that potentially could benefit patients with diabetes and renal dysfunction. Considerable evidence is available to support the contention that improved glycemic control may have beneficial effects on the development and progression of diabetic renal disease. Maximal benefits of improved glycemia occur when instituted before the onset of macroalbuminuria. Once overt diabetic nephropathy is established, improved glycemic control may not be beneficial. Current evidence indicates that a glycosylated hemoglobin level of less than 8.1% should be the glycemic goal. At this level, the risk of developing micro-albuminuria is substantially reduced, and the risk of hypoglycemia is minimized. Most studies have been conducted in type I diabetes, and the results have been extrapolated to type II diabetes. Whether improved glycemic control will be equally beneficial in the nephropathy of type II diabetes has yet to be determined. Although some scientific evidence supports dietary protein restriction in patients with diabetic nephropathy, the extent of restriction needed for optimal benefits and minimal side effects remains to be determined. On the basis of current information, patients with both types of diabetes who have evidence of nephropathy should have protein limited to the recommended dietary allowance for adults (0.8 g/kg of body weight per day or approximately 10% of total daily caloric intake), and protein should be derived primarily from vegetable and lean animal sources. End-stage renal disease is not inevitable in patients with diabetic nephropathy. Normalization of glucose levels and modification of protein intake can favorably influence the course of diabetes-related kidney disease.

Habitual dietary calcium intake and blood pressure change around the menopause: a longitudinal study.

In a 10-year follow-up study, blood pressure and dietary intake were measured annually in 167 healthy perimenopausal normotensive women. Their initial ages ranged between 49 and 56 years and habitual calcium intake between 560 and 2580 mg/day (mean 1110 mg/day); they lived in the mixed rural/industrial community of Ede, the Netherlands. The longitudinal design provided an opportunity to study the 'natural history' of blood pressure and the effect of dietary calcium during and after the period of ovarian failure. For data analysis, person-time experience was divided into three menopausal periods. Based on years relative to menopause three menopausal cohorts were created starting 2 years before, 2 years after and 6 years after menopause, each was followed for 4 years. Changes in systolic (SBP) and diastolic blood pressure (DBP) during the menopausal periods were adjusted for change in body mass index and other relevant variables in multiple regression analysis. An average decline in SBP of 6 mm Hg was observed in the period of 2 years before menopause to 6 years after menopause, and an increase of almost 5 mm Hg in the period between 6 and 10 years after menopause. A significant change in DBP was not observed. Neither changes in, nor the absolute level of, calcium intake showed any relevant association with blood pressure change. Ovarian failure seems to reverse temporarily the increase in blood pressure due to aging. The results do not suggest that a habitual calcium intake exceeding 800-1000 mg/day (the current Recommended Daily Allowance for adults) is effective in preventing hypertension during the peri- and postmenopausal period.

Habitual dietary calcium intake and cortical bone loss in perimenopausal women: A longitudinal study

During an 8-year follow-up study, the effect of habitual dietary calcium intake on cortical bone loss in 154 healthy perimenopausal women was examined. Dietary calcium intake, determined by the cross-check dietary history method, and cortical bone mineral content of the radius were measured annually. Habitual dietary calcium intake was calculated as the mean of the estimated daily dietary calcium intake during the follow-up period. The women were classified according to their habitual calcium intake: those with an intake below 800 mg/day (n = 28), between 800 and 1350 mg/day (n = 95), and above 1350 mg/day (n = 31). The results show a continuous significant loss of cortical bone in all groups, amounting yearly to 1.3 +/- 0.25, 1.5 +/- 0.10, and 1.9 +/- 0.23% (mean +/- SE) for the groups with a low, medium, and high habitual calcium intake, respectively (P less than 0.01). The differences among the three groups did not reach statistical significance (P = 0.11). Body mass index was found to be positively correlated with the negative changes in cortical bone mineral density (r = 0.32, P less than 0.01), even after adjustments had been made for confounding factors. It is concluded that a habitual calcium intake exceeding 800 mg/day (the current Recommended Daily Allowance for adults) is ineffective in preventing cortical bone loss during early menopause. Body mass index is of major importance for the perimenopausal bone loss.

Vitamin A gastrointestinal absorption in persons with Down's syndrome

The total daily vitamin A intake, physical signs associated with vitamin A deficiency, and the response to a vitamin A challenge were studied in 33 patients with Down's syndrome and in 14 intellectually normal persons (comparison group). The evaluation of detailed dietary histories revealed that the study subjects' mean daily vitamin A intake was similar to the recommended daily allowance for adults and that there was no significant difference of the mean daily vitamin A intake between study and comparison groups (5029 IU and 5706 IU, respectively). Subjects with Down's syndrome had more symptoms usually seen in patients with hypovitaminosis A than the persons in the comparison group. The baseline serum vitamin A levels in the Down's syndrome and comparison groups were within the normal range (106.0 micrograms/dl and 136.5 micrograms/dl, respectively). The vitamin A absorption curve of persons with Down's syndrome paralleled that of normal individuals and no significant difference of vitamin A levels between study and comparison groups was observed except for the 6-h values. Also, the absorption differential (delta = 3-h value + 6-h value/2-O-h value) did not show a significant difference between the two groups. Thus, these investigations do not support previous reports of significantly decreased vitamin A absorption in individuals with Down's syndrome.

Calcium Supplementation of Cottage Cheese

Cottage cheese (100g) provides only 6% of the calcium Recommended Daily Allowance for adults. Samples of fresh cheese were supplemented with calcium salts (chloride, lactate, or phosphate monobasic) to double the calcium content of the cheese to approximately 145mg/100g, and the effects of the supplementation on taste and microbial stability were studied. Supplementations did not affect pH or microbial stability during 21 d of refrigerated storage. Sensory evaluation results of a 12-member taste panel showed higher flavor and preference scores for control than for all supplemented samples (P<.05) but no difference in odor, color, or texture. Overall, chloride appeared to be preferable for calcium content supplementation because only .26% (wt/wt) of the salt was required to obtain the desired calcium content level and the mineral was evenly distributed in the cheese.

The effect of long-term increased protein administration on mineral metabolism and kidney function in the rat. II. Kidney function and bone mineralization

In the Federal Republic of Germany the average daily protein intake exceeds the Recommended Dietary Allowances for adults (0.8 g protein/kg body weight) by about 100%. On the other hand calcium intake is below the recommendations for certain age groups. Protein-induced hypercalciuria involves the risk of depletion of skeletal calcium stores, especially for older people who have a decreased absorption capacity for calcium. As a result of our study we postulate, that an altered renal function probably is one inducing factor of hypercalciuria. While urea excretion and serum urea concentration increased with an elevated dietary protein content from 13 to 26 or 40 J%, glomerular filtration rate remained unchanged. Fractional tubular reabsorption of calcium was significantly reduced by about 3% with increased endogenous acid production and renal excretion of hydrogen ions (first part of the study), which were accompanying a higher protein intake of 40 J% compared to 13 J% protein in the control group. Increasing the phosphorus content of the diet improved the reabsorption of calcium and magnesium. The kidneys of rats fed diets high in protein and phosphorus were hypertrophied. Histology of the kidneys showed signs of glomerulonephrosis. While the calcium content of the femora was slightly reduced with a higher protein intake of 40 compared to 13 J%, the magnesium content was increased (after 61 weeks: calcium from 261.4 to 257.1 mg/g dry fat-free wt [p less than or equal to 0.05]; magnesium from 3.2 to 3.5 mg/g dry fat-free wt [p less than or equal to 0.001]). Calcium and magnesium metabolism depends not only on the level of protein intake, but also on its interrelation with the dietary phosphorus content. With continuous high protein intake higher intakes for calcium, phosphorus and magnesium should be recommended, especially for older people.

Ca, Fe and Zn Content of‘Jewel’Sweet Potato Greens as Affected by Harvesting Practices

ABSTRACTA total of 64 “Jewel” sweet potato green samples collected at the end of the growing season, were analyzed to determine and compare the effects of multiple topping on dry matter, calcium, iron and zinc contents of “younger” 4‐inch leaf and stem‐petiole tips with “older” 4‐inch portions of the same material. Older material contained the highest concentration of the minerals, and the concentration in both “young” and “old” plant material wasunaffected by yearly planting. When the mineral content was compared to the Recommended Daily Dietary Allowance for adults it was relatively good.

Proximate and mineral content of restaurant steak meals

Restaurant steak meals were analyzed for proximate and mineral composition by standard methodology. Nutritional adequacy of the meals was determined by comparing analyzed values with Recommended Dietary Allowances for adults. The meals were considered to be adequate in a nutrient if they provided at least one-third the RDA for that nutrient. Analyzed values were also compared with values obtained from food composition tables. The results of this study indicate that: 1. Restaurant steak meals differ significantly in weight of meal components, proximate components, and mineral components. 2. Although the meals were adequate in kilocalories and protein, they could be considered to be excessive since they provided more than 50% of the RDA for energy and more than 100% of the RDA for protein. 3. The meals can be considered inadequate in calcium for both men and women (only 16% of the RDA) and in iron for women (only 25% of the RDA). 4. Tables of food composition are useful in predicting the proximate and mineral composition of restaurant steak meals.