Adequate Intake Of Vitamin Research Articles

Hungarian Diet and Nutritional Status Survey – The OTAP2009 study. III. Vitamin intake of the Hungarian population

For the healthy status the adequate intake of vitamins is essential. The Hungarian Diet and Nutritional Status Survey - joining to the European Health Interview Survey - studied the dietary habits of the Hungarian population. This work presents the vitamins intake. The intake of all water soluble vitamins, vitamin E and D were significantly higher in men than in women. Favourable phenomena were the increased β-carotene and vitamin C intakes in men and women compared to the earlier data. Intakes of vitamin C, B1-, B2-, B6- and B12, and niacin meet the recommendations. Crucially low intakes of vitamin D and folate were calculated in both genders, particularly in the elders, mainly in case of vitamin D. Imperfect intakes of panthotenic acid and biotin were also observed. For maintaining the adequate vitamin supply and for prevention of vitamin deficiency, diversified nutrition, information of the population on the basic principles of healthy nutrition and availability of healthy food are essential.

Vitamin D: Extraskeletal Health

Vitamin D deficiency is the most common nutritional deficiency and likely the most common medical condition in the world. There is a multitude of causes of vitamin D deficiency, but the major cause has been the lack of appreciation that the body requires 5- to 10-fold higher intakes than is currently recommended by the Institute of Medicine and other health agencies. It is likely that our hunter gatherer fore-fathers being exposed to sunlight on a daily basis were making several thousand IU of vitamin D a day. The fact that 100 IU of vitamin D prevented overt signs of rickets led to the false security that ingesting twice this amount was more than adequate to satisfy the body’s vitamin D requirement. Although this may be true for preventing overt skeletal deformities associated with rickets, there is now overwhelming and compelling scientific and epidemiologic data suggesting that the human body requires a blood level of 25(OH)D above 30 ng/mL for maximum health. The likely reason is that essentially every tissue and cell in the body has a VDR and thus, to have enough vitamin D to satisfy all of these cellular requirements, the blood level of 25(OH)D needs to be above 30 ng/mL. It has been estimated that for every 100 IU of vitamin D ingested that the blood level of 25(OH)D increases by 1 ng/mL. Thus to theoretically achieve a blood level above 30 ng/mL requires the ingestion of 3000 IU of vitamin D a day. There is evidence, however, that when the blood levels of 25(OH)D are less than 15 ng/mL, the body is able to more efficiently use vitamin D to raise the blood level to about 20 ng/mL. To raise the blood level of 25(OH)D above 20 ng/mL requires the ingestion of 100 IU of vitamin D for every 1-ng increase; therefore to increase the blood level to the minimum 30 ng/mL requires the ingestion of at least 1000 IU of vitamin D a day for adults. There is a great need to significantly increase the recommended adequate intakes of vitamin D. All neonates during the first year of life should take at least 400 IU/d of vitamin D, and increasing it to 1000 IU/d may provide additional health benefits. Children 1 year and older should take at least 400 IU/d of vitamin D as recently recommended by the American Academy of Pediatrics, but they should consider increasing intake up to 2000 IU/d derive maximum health benefits from vitamin D. Prepubertal and teenage girls who received 2000 IU of vitamin D per day for a year showed improvement in their musculoskeletal health with no untoward toxicity. All adults should be taking 2000 IU of vitamin D per day. A recent study reported that adults who took 50,000 IU of vitamin D once every 2 weeks, which is equivalent to taking 3000 IU of vitamin D a day, for up to 6 years was effective in maintaining blood levels of 25(OH)D of between 40 and 60 ng/mL without any toxicity. There is no downside to increasing either a child’s or adult’s vitamin D intake, with the exception of acquired disorders such as granulomatous diseases including sarcoidosis and tuberculosis, as well as some lymphomas with activated macrophages that produce 1,25(OH)2D3 in an unregulated fashion.

Antioxidant Supplementation during Exercise Training

High levels of reactive oxygen species (ROS) produced in skeletal muscle during exercise have been associated with muscle damage and impaired muscle function. Supporting endogenous defence systems with additional oral doses of antioxidants has received much attention as a noninvasive strategy to prevent or reduce oxidative stress, decrease muscle damage and improve exercise performance. Over 150 articles have been published on this topic, with almost all of these being small-scale, low-quality studies. The consistent finding is that antioxidant supplementation attenuates exercise-induced oxidative stress. However, any physiological implications of this have yet to be consistently demonstrated, with most studies reporting no effects on exercise-induced muscle damage and performance. Moreover, a growing body of evidence indicates detrimental effects of antioxidant supplementation on the health and performance benefits of exercise training. Indeed, although ROS are associated with harmful biological events, they are also essential to the development and optimal function of every cell. The aim of this review is to present and discuss 23 studies that have shown that antioxidant supplementation interferes with exercise training-induced adaptations. The main findings of these studies are that, in certain situations, loading the cell with high doses of antioxidants leads to a blunting of the positive effects of exercise training and interferes with important ROS-mediated physiological processes, such as vasodilation and insulin signalling. More research is needed to produce evidence-based guidelines regarding the use of antioxidant supplementation during exercise training. We recommend that an adequate intake of vitamins and minerals through a varied and balanced diet remains the best approach to maintain the optimal antioxidant status in exercising individuals.

Influence of vitamin D levels on bone mineral density and osteoporosis

BACKGROUND AND OBJECTIVES:The effects of vitamin D on bone mass remain to be understood. This study was conducted with the objective of evaluating the influence of 25-hydroxyvitamin D (25OHD) levels on bone mineral density (BMD) among Saudi nationals.DESIGN AND SETTING:Cross-sectional study carried out at university hospital from 1 February 2008 to 31 May 2008.SUBJECTS AND METHODS:Healthy Saudi men and women in the peak bone mass (PBM) age group and those aged ≥50 years were recruited from the outpatient department of King Fahd University Hospital, Al Khobar, Saudi Arabia, between February 1, 2008, and May 31, 2008. Patient age and sex were documented, and body mass index was calculated. Hematological, biochemical, and serum 25OHD tests were performed. BMD was determined by dual-energy x-ray absorptiometry of the upper femur and lumbar spine. Patients were divided into three groups, based on their 25OHD level.RESULTS:Data from 400 patients were analyzed. Among individuals with a normal 25OHD level, 50% of women and 7% of men in the PBM age group and 26.4% of women and 49.2% of men aged ≥50 years had low bone mass. In patients with 25OHD insufficiency, 84.2% of women and 88.9% of men in the PBM age group and 83.3% of women and 80% of men aged ≥50 years had low bone mass. Results for patients with 25OHD deficiency revealed that none of the men and women in the PBM age group or ≥50 years old had normal BMD. Significant positive correlations between 25OHD level and BMD and significant negative correlations with parathyroid hormone were shown in most of the groups.CONCLUSIONS:This study showed that the vitamin D level significantly influences BMD reading among Saudi individuals. Evaluation and treatment of hypovitaminosis D should be considered during management of low bone mass.

Cod liver oil. A natural Vitamin D for preserving health

Vitamin D deficiency is pandemic in industrialized countries due to life-style changes. Recent studies suggest that besides bone-metabolism, vitamin D plays a central role in basic cell function like multiplication, differentiation and metabolism. This may explain that low vitamin D levels represent a risk factor for several apparently different diseases such as infective, autoimmune, neurodegenerative and cardiovascular diseases, as well as diabetes, osteoporosis and cancer. Accumulating evidences suggest that an adequate intake of vitamin D may significantly decrease prevalence and clinical outcome of these diseases. Estimated reduction of the economic burden might reach about 10 percent through normalizing vitamin D levels for these diseases. However, high doses of vitamin D monotherapy needs precaution for potential adverse effects and it should be substituted with the recommended doses of vitamin D in combination with synergistic vitamin A and omega 3 fatty acids, such as cod liver oil.

Reduced bone mineral density is not associated with significantly reduced bone quality in men and women practicing long‐term calorie restriction with adequate nutrition

Calorie restriction (CR) reduces bone quantity but not bone quality in rodents. Nothing is known regarding the long-term effects of CR with adequate intake of vitamin and minerals on bone quantity and quality in middle-aged lean individuals. In this study, we evaluated body composition, bone mineral density (BMD), and serum markers of bone turnover and inflammation in 32 volunteers who had been eating a CR diet (approximately 35% less calories than controls) for an average of 6.8 ± 5.2 years (mean age 52.7 ± 10.3 years) and 32 age- and sex-matched sedentary controls eating Western diets (WD). In a subgroup of 10 CR and 10 WD volunteers, we also measured trabecular bone (TB) microarchitecture of the distal radius using high-resolution magnetic resonance imaging. We found that the CR volunteers had significantly lower body mass index than the WD volunteers (18.9 ± 1.2 vs. 26.5 ± 2.2 kg m(-2) ; P = 0.0001). BMD of the lumbar spine (0.870 ± 0.11 vs. 1.138 ± 0.12 g cm(-2) , P = 0.0001) and hip (0.806 ± 0.12 vs. 1.047 ± 0.12 g cm(-2) , P = 0.0001) was also lower in the CR than in the WD group. Serum C-terminal telopeptide and bone-specific alkaline phosphatase concentration were similar between groups, while serum C-reactive protein (0.19 ± 0.26 vs. 1.46 ± 1.56 mg L(-1) , P = 0.0001) was lower in the CR group. Trabecular bone microarchitecture parameters such as the erosion index (0.916 ± 0.087 vs. 0.877 ± 0.088; P = 0.739) and surface-to-curve ratio (10.3 ± 1.4 vs. 12.1 ± 2.1, P = 0.440) were not significantly different between groups. These findings suggest that markedly reduced BMD is not associated with significantly reduced bone quality in middle-aged men and women practicing long-term calorie restriction with adequate nutrition.

Milk fortified with the current adequate intake for vitamin D (5 microg) increases serum 25-hydroxyvitamin D compared to control milk but is not sufficient to prevent a seasonal decline in young women.

Low vitamin D status in women of childbearing age may have implications for health. Vitamin D status of New Zealanders (NZ), based on low serum 25-hydroxyvitamin D (25OHD) is suboptimal. Vitamin D status may be improved with supplements and/or fortified foods. Recently an Adequate Intake (AI) for Australia and NZ was set at 5 microg/d vitamin D. We aimed to determine the effect of daily consumption of milk powder fortified with 5 microg vitamin D3 on serum 25OHD concentration over 12 wks. 73 non-pregnant women (18 - 47 y) living in Dunedin, NZ (46 degrees S) were randomised to receive either unfortified (control) or fortified (5 microg vitamin D3) milk for 12 wks from January to April. Mean 25OHD was similar between groups at week 0 (control 74 vs 76 nmol/L) and fell significantly in both groups over the 12 weeks (control 53 nmol/L, fortified 65 nmol/L; p < 0.001). After 12 wks the fortified milk group had a serum 25OHD 19% (95% CI; 7, 32%) higher (10 nmol/L) than the control group after adjusting for baseline levels (p < 0.001). Daily consumption of fortified milk providing the current AI of 5 microg day vitamin D3 for 12 weeks resulted in higher 25OHD concentrations than control milk. This dose was not sufficient to prevent the seasonal decline in 25OHD. This study suggests an AI of 5 microg may be inadequate for New Zealanders to allow for seasonal changes in sunlight exposure, and is unlikely sufficient for other populations with low sunlight exposure.

Response to: Towards an adequate intake of vitamin D. An advisory report of the Health Council of the Netherlands

Response to: Towards an adequate intake of vitamin D. An advisory report of the Health Council of the Netherlands

Towards an adequate intake of vitamin D. An advisory report of the Health Council of the Netherlands

Towards an adequate intake of vitamin D. An advisory report of the Health Council of the Netherlands

Children consuming cassava as a staple food are at risk for inadequate zinc, iron, and vitamin A intake.

Cassava contains little zinc, iron, and β-carotene, yet it is the primary staple crop of over 250 million Africans. This study used a 24-hour dietary recall to test the hypothesis that among healthy children aged 2–5 years in Nigeria and Kenya, cassava’s contribution to the childrens’ daily diets is inversely related to intakes of zinc, iron, and vitamin A. Dietary and demographic data and anthropometric measurements were collected from 449 Kenyan and 793 Nigerian children. Among Kenyan children 89% derived at least 25% of their dietary energy from cassava, while among the Nigerian children 31% derived at least 25% of energy from cassava. Spearman’s correlation coefficient between the fraction of dietary energy obtained from cassava and vitamin A intake was r = −0.15, P < 0.0001, zinc intake was r = −0.11, P < 0.0001 and iron intake was r = −0.36, P < 0.0001. In Kenya, 59% of children consumed adequate vitamin A, 22% iron, and 31% zinc. In Nigeria, 17% of children had adequate intake of vitamin A, 57% iron, and 41% zinc. Consumption of cassava is a risk factor for inadequate vitamin A, zinc and/or iron intake.

Intakes and Major Food Sources of Vitamins A and E of Korean Adults Living in Seoul and Gyeonggi Province

To determine vitamin A and E intakes and their food sources, dietary intakes were collected by three consecutive 24- hour recalls from 192 adults living in Seoul and Gyeonggi Province, Korea. The mean vitamin A, retinol and β-caro- tene intakes were 1240.1 ± 1101.1 μg retinol equivalent/day (693.3 ± 563.2 μg retinol activity equivalent/day), 182.6 ± 149.5 μg/ day and 5443.3 ± 6365.5 μg/day, respectively. Only 9.4% of the subjects consumed less than the Korean Estimated Average Requirement for vitamin A. The mean vitamin E intake was 6.03 ± 2.54 mg α-tocopherol equiva- lent/ day. The α-tocopherol and γ-tocopherol intakes were 4.83 ± 2.03 and 5.57 ± 3.41 mg/day, respectively. Most of the subjects (93.8%) consumed less than the Korean Adequate Intake for vitamin E. The major food sources of vi- tamin A were sweet potato, carrot, red pepper powder, spinach, and citrus fruit, and the top 30 foods provided 91.5% of total Plant foods provided 81.0% and animalderived foods 10.5% of the vitamin A intake from the top 30 foods. The ma- jor food sources of vitamin E were soybean oil, red pepper powder, Ramyeon (cup noodles), spinach, and egg. The top 30 foods provided 78.0% of total vitamin E intake. Plant foods provided 61.3% and animal-derived foods 15.9% of the vitamin E intake from the top 30 foods. In conclusion, the vitamin A intake of the Korean adults in this study was ge-ne- rally adequate, but the vitamin E intake of many subjects was inadequate. Therefore, nutritional education may be of benefit to Korean adults to increase their vitamin E intake. (Korean J Nutr 2010; 43 (6): 628 ~ 637)

Vitamin D and calcium insufficiency-related chronic diseases: molecular and cellular pathophysiology

A compromised vitamin D status, characterized by low 25-hydroxyvitamin D (25-(OH)D) serum levels, and a nutritional calcium deficit are widely encountered in European and North American countries, independent of age or gender. Both conditions are linked to the pathogenesis of many degenerative, malignant, inflammatory and metabolic diseases. Studies on tissue-specific expression and activity of vitamin D metabolizing enzymes, 25-(OH)D-1 alpha-hydroxylase and 25-(OH)D-24-hydroxylase, and of the extracellular calcium-sensing receptor (CaR) have led to the understanding of how, in non-renal tissues and cellular systems, locally produced 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)) and extracellular Ca(2+) act jointly as key regulators of cellular proliferation, differentiation and function. Impairment of cooperative signalling from the 1,25-(OH)(2)D(3)-activated vitamin D receptor (VDR) and from the CaR in vitamin D and calcium insufficiency causes cellular dysfunction in many organs and biological systems, and, therefore, increases the risk of diseases, particularly of osteoporosis, colorectal and breast cancer, inflammatory bowel disease, insulin-dependent diabetes mellitus type I, metabolic syndrome, diabetes mellitus type II, hypertension and cardiovascular disease. Understanding the underlying molecular and cellular processes provides a rationale for advocating adequate intake of vitamin D and calcium in all populations, thereby preventing many chronic diseases worldwide.

Towards an adequate intake of vitamin D. An advisory report of the Health Council of the Netherlands

In this report, the Health Council of the Netherlands advises the government on the best policies to achieve an adequate vitamin D supply for the Dutch population. People with a dark skin, those who spend little time outdoors, pregnant and lactating women, veiled women, elderly and children who do not receive vitamin D supplements or infant formula are at risk of vitamin D deficiency. To improve this, more consistent information about vitamin D should be provided. Spending at least 15 min a day outdoors in combination with a healthy diet generates sufficient vitamin D in children and adults with a light skin. All other groups need additional vitamin D from supplements (10-20 microg/day). Fortified foods can only provide part of the additional vitamin D needed.

TREATMENT and prevention of kwashiorkor.

Recent research carried out on kwashiorkor in Kampala, Uganda, is discussed. The first essential in both the treatment and the prevention of this disease being a diet rich in protein (preferably animal protein, to ensure an adequate intake of vitamin B(12) and a satisfactory mixture of amino-acids), methods of incorporating sufficient protein into children's diets were investigated.For the treatment of severe cases, two high-protein diets-one based on animal protein, the other on plant protein-gave good results. In the first, the protein was obtained from dried skimmed milk and a calcium caseinate preparation known as Casilan; in the second, it was supplied by soya. Some vitamin B(12), which is lacking in the soya itself, was added to the second diet in order to ensure satisfactory weight gains.With regard to prevention, the author points out that although it is theoretically simple there are serious practical difficulties. The best sources of protein-milk, meat, and fish-are unfortunately, at present, too expensive for general consumption in Uganda. Therefore, the best possible use of plant protein must be made for the time being. In this connexion, the author recommends investigating the value of sunflower, which grows more easily in Uganda than soya. He feels that soya, sunflower, and maize could probably be combined to provide a mixture of amino-acids which-though not as perfect as that found in animal proteins-would be very satisfactory.

Vitamin D status and common risk factors for bone fragility as determinants of quantitative ultrasound variables in a nationally representative population sample

Calcaneal quantitative ultrasound (QUS) can predict bone strength and fracture risk. Bone fragility has no single cause but results from a complex interplay of several etiologic or contributing factors. Vitamin D is essential for bone health even though it is still unclear how much of this vitamin is required to maintain bone strength and prevent fractures. Measurements of serum 25-hydroxyvitamin D [S-25(OH)D] have indicated a high prevalence of inadequate vitamin D status in a number of studies mostly based on selected study populations. The objective of this study was to examine the associations between S-25(OH)D, common risk factors for bone fragility, and QUS variables in a large unselected population sample.The study population consisted of 2736 men and 3299 women from a nationally representative population sample, aged 30 years or over. Information on lifestyle was elicited by means of interviews and questionnaires. Body fat mass was estimated using an impedance-meter. S-25(OH)D was measured by radioimmunoassay. Calcaneal QUS was performed on the Hologic Sahara apparatus recording broadband ultrasound attenuation (BUA) and speed of sound (SOS). The potential determinants of BUA and SOS were analysed using separate multiple linear regression models for men and women.S-25(OH)D proved to be an independent determinant of BUA (P<0.0001 for men, P<0.001 for women) and SOS (P<0.0001 for men, P<0.05 for women). BUA was also independently associated with age, height, weight, alcohol consumption, and postmenopausal status in women, and with weight, alcohol consumption, smoking and physical activity in men. All of the above variables, except for weight in women, were also found to be independent determinants of SOS in both men and women. A reverse association was found between S-25(OH)D and adiposity in spite of higher intakes of vitamin D in those with higher fat mass.In this unselected sample of men and women, vitamin D status, several lifestyle factors and physical characteristics proved to be significant determinants of BUA and SOS. Inadequate vitamin D status was common, and measures ensuring adequate intakes of vitamin D in the population thus deserve continued attention. Obesity should be taken into account in future assessments of vitamin D status in Finland as in other countries.

Vitamin A and cervical squamous intraepithelial lesions

Sir, The vast majority of women who come into contact with Human Papilloma Virus (HPV) do not develop any cervical lesions 1. Among those who do, few still present with a high-grade squamous intraepithelial lesion (HSIL) of the cervix. Brazil has a high incidence of cervical cancer, mostly in the northeast region where poverty and malnutrition rates are high 2. Previous studies have shown a high prevalence of low vitamin A levels in this population, which has been considered a public health problem 3. The progression of the disease may be multifactorial, presenting many co-factors, which associated with HPV infection could lead to an increased risk of developing HSIL. Nutritional factors are gradually taking on an important role in understanding the pathophysiology of HPV infection and may help to explain the mechanisms that result in the progression of intraepithelial lesions in some women 1. Although still uncertain, the hypothesis has been advanced that an adequate intake of vitamin A could protect individuals against the development of squamous intraepithelial lesions. Experiments in animals have shown that vitamin A deficiency predisposes to the development of these lesions 4. The deficit of retinoids in turn, was associated with an increased risk of gastrointestinal tract, genito-urinary and skin cancer 5. We have carried out a cross-sectional pilot study to assess the levels of Vitamin A by means of the Bessey–Lowrey method, modified by Araujo & Flores 3 in 40 women aged between 14 and 48 years who had colposcopy directed biopsy of the cervix in the Cervical Pathology and Colposcopy Service in the Federal University of Ceara (UFC) in Fortaleza, Brazil, between July 2004 and July 2005. Of these women, 17 (42.5%) had negative results for squamous intraepithelial lesions (SILs). In 23 (57.5%) cases, the histological diagnosis pointed to SIL, and 18 (45%) had low-grade (LSIL), while five (12.5%) had high grade (HSIL). The serum levels of vitamin A ranged from 9.1 g/dl to 108.4 mg/dl. Vitamin A levels below 20 μg/dl (low) were found in only 1/17 (6%) women without a cervical lesion, but 4/18 (22%) among those with LSIL and 5/5 (100%) of HSIL. There was no significant difference between serum vitamin A levels for women with negative biopsies and with low-grade SIL, but there may be still lower levels in women with high-grade lesions. Vitamin A can perhaps be an important co-factor in the development of SILs, but more comprehensive studies and intervention trials with vitamin supplementation are necessary to evaluate this.

Estado nutricional e consumo alimentar de adolescentes da rede pública de ensino da cidade de São Mateus do Sul, Paraná, Brasil

OBJETIVOS: caracterizar o estado nutricional e consumo alimentar de adolescentes da rede pública de ensino de São Mateus do Sul, Paraná, Brasil. MÉTODOS: o Índice de Massa Corporal foi calculado e classificado pela proposta da Organização Mundial da Saúde. O consumo alimentar foi obtido pelo Questionário de Freqüência de Consumo Alimentar. Foi utilizada análise descritiva, de freqüência e teste t de Student com p&lt;0,05. RESULTADOS: a maioria dos indivíduos apresentou estado nutricional normal (84% eutróficos, 12% sobrepeso/obesidade e 4% baixo peso). A dieta caracterizou-se por consumo energético adequado, com distribuição de macronutrientes de acordo com as recomendações, sendo maior nos meninos do que nas meninas. Noventa por cento dos adolescentes consumiam ácidos graxos em excesso. Verificou-se consumo adequado de vitamina C (287 mg meninos e 328 mg meninas) e ferro (27 e 21 mg, respectivamente). O consumo de ferro diferiu estatisticamente entre os sexos (t=3,765; p&lt;0,001). CONCLUSÕES: as anormalidades encontradas na alimentação evidenciam a necessidade de conhecer e avaliar o tipo de alimentação oferecida aos alunos, a fim de elaborar estratégias de intervenção dentro e fora das escolas, além de auxiliar a prevenção de problemas de saúde relacionados à alimentação.

High prevalence of hyperhomocysteinemia in critically ill patients: Vascular damage and adequate vitamin intake

Summary Aims To determine the prevalence of hyperhomocysteinaemia in critically ill patients and its relationship with endothelial damage and vitamin intake. Methods Total antioxidant capacity, lipid peroxides, and carbonyl group in plasma were measured by spectrophotometry. Homocysteine, D-dimer, B12 vitamin and folic acid levels were determined by immunoassay. Daily diet records were compared with vitamin recommendations in 40 consecutive critically ill patients. Results Homocysteinaemia on day 7 was higher in patients with 12 and folic acid than in patients with higher intakes (16.3 ± 3.1 μm/L vs. 9.3 ± 54 μm/L, p r 2 = 0.65, p r 2 = 0.58, p r 2 = −0.57, p r 2 = 0.47, p Conclusions The present findings appear to support the maintenance of an adequate vitamin intake in critically ill patients to reduce their risk of hyperhomocysteinemia, and therefore microthromboses. However, controlled clinical trials are required to establish any causal relationships.

I-Cell Disease (Mucolipidosis II) Presenting as Neonatal Fractures: A Case for Continued Monitoring of Serum Parathyroid Hormone Levels.

A severe form of I-cell disease (mucolipidosis II) can present in the newborn period as multiple fractures. The bone disease in these patients is believed to be due to hyperparathyroidism. We report a case where bone disease was present at birth but the parathyroid hormone levels were initially normal and did not increase until 37 d of age. Supplemention with vitamin D was needed to normalize the parathyroid hormone levels despite adequate intake of vitamin D, calcium and phosphorus. We suggest that in patients with I-cell disease, continued evaluation for hyperparathyroidism may be necessary despite initial normal parathyroid hormone levels.

The role of vitamin E in the diet.

Abstract The last decade has seen many developments in our understanding of vitamin E, its transport and metabolism, and its potential role in the prevention of chronic disease. Of the eight fat-soluble substances comprising vitamin E, α-tocopherol has emerged as central to vitamin E activity in the body, its concentration in the plasma being governed by α-tocopherol transfer protein and maintained in a narrow range. Although new insights into the role of habitual fat intake in determining human requirements for vitamin E have been gained, uncertainties remain and estimates of requirements differ considerably between authorities. Investigation of the potential of this potent chain-breaking antioxidant to prevent or delay conditions thought to be associated with oxidative stress, including cardiovascular disease, cancer, Alzheimer's disease and Parkinson's disease, has challenged nutritionists to reconsider optimal intakes of vitamin E. High-dose supplementation has proved ineffective in reducing risk and may even be associated with increased risk; yet, new evidence suggests that a lifetime diet rich in α-tocopherol may provide protection against heart disease and cancer. Intakes of α-tocopherol are low in some western populations, which may in part be the result of advice to consume low-fat diets, intended to help address rising rates of obesity. An increased focus on fat quality, consistent with advice stemming from the cardiovascular literature, will help ensure adequate intakes of vitamin E in the context of diets moderate in total fat.