Reference Daily Intake

About: Reference Daily Intake is a research topic. Over the lifetime, 1564 publications have been published within this topic receiving 52794 citations.

Characteristics of fats in Japanese diets and current recommendations

Abstract: Although there is no firm evidence to support the "ideal" or even "appropriate" healthy level of dietary fat, the habitual fat consumption pattern in Japan seems to be a criterion for the recommended allowance both in the quantitative and qualitative points of view as judged from the life expectancy and the incidence of degenerative diseases. The new recommended dietary allowance of Japan, fifth revision effective for five years starting in 1995, adopted dietary fat levels of 20-25 energy percent, the ratio of saturated, monounsaturated, and polyunsaturated fatty acids at 1:1.5:1 and the ratio of n-6/n-3 at 4. The recommended fat level is similar to that previously consumed in Japan, and is even lower than that in diets used to treat hyperlipidemia in Western countries, current recommendations in those countries being 30 energy percent fat. Convincing data for the beneficial effects of n-3 polyunsaturated fatty acids on human health, in particular for healthy people, have been presented in only a few reports. However, the recommended n-6/n-3 ratio of 4 seems reasonable compared with the ratio of around 10 in other developed countries. In this context, it is more important to fully understand the nutritional and physiological roles of fat in healthy people rather than in those with chronic disease. At present, the low-fat dietary pattern in Japan appears to be a healthy way of eating.

Clinical utility of vitamin d testing: an evidence-based analysis.

Abstract: UNLABELLED This report from the Medical Advisory Secretariat (MAS) was intended to evaluate the clinical utility of vitamin D testing in average risk Canadians and in those with kidney disease. As a separate analysis, this report also includes a systematic literature review of the prevalence of vitamin D deficiency in these two subgroups.This evaluation did not set out to determine the serum vitamin D thresholds that might apply to non-bone health outcomes. For bone health outcomes, no high or moderate quality evidence could be found to support a target serum level above 50 nmol/L. Similarly, no high or moderate quality evidence could be found to support vitamin D's effects in non-bone health outcomes, other than falls. VITAMIN D: Vitamin D is a lipid soluble vitamin that acts as a hormone. It stimulates intestinal calcium absorption and is important in maintaining adequate phosphate levels for bone mineralization, bone growth, and remodelling. It's also believed to be involved in the regulation of cell growth proliferation and apoptosis (programmed cell death), as well as modulation of the immune system and other functions. Alone or in combination with calcium, Vitamin D has also been shown to reduce the risk of fractures in elderly men (≥ 65 years), postmenopausal women, and the risk of falls in community-dwelling seniors. However, in a comprehensive systematic review, inconsistent results were found concerning the effects of vitamin D in conditions such as cancer, all-cause mortality, and cardiovascular disease. In fact, no high or moderate quality evidence could be found concerning the effects of vitamin D in such non-bone health outcomes. Given the uncertainties surrounding the effects of vitamin D in non-bone health related outcomes, it was decided that this evaluation should focus on falls and the effects of vitamin D in bone health and exclusively within average-risk individuals and patients with kidney disease. Synthesis of vitamin D occurs naturally in the skin through exposure to ultraviolet B (UVB) radiation from sunlight, but it can also be obtained from dietary sources including fortified foods, and supplements. Foods rich in vitamin D include fatty fish, egg yolks, fish liver oil, and some types of mushrooms. Since it is usually difficult to obtain sufficient vitamin D from non-fortified foods, either due to low content or infrequent use, most vitamin D is obtained from fortified foods, exposure to sunlight, and supplements. CLINICAL NEED CONDITION AND TARGET POPULATION Vitamin D deficiency may lead to rickets in infants and osteomalacia in adults. Factors believed to be associated with vitamin D deficiency include: darker skin pigmentation,winter season,living at higher latitudes,skin coverage,kidney disease,malabsorption syndromes such as Crohn's disease, cystic fibrosis, andgenetic factors.Patients with chronic kidney disease (CKD) are at a higher risk of vitamin D deficiency due to either renal losses or decreased synthesis of 1,25-dihydroxyvitamin D. Health Canada currently recommends that, until the daily recommended intakes (DRI) for vitamin D are updated, Canada's Food Guide (Eating Well with Canada's Food Guide) should be followed with respect to vitamin D intake. Issued in 2007, the Guide recommends that Canadians consume two cups (500 ml) of fortified milk or fortified soy beverages daily in order to obtain a daily intake of 200 IU. In addition, men and women over the age of 50 should take 400 IU of vitamin D supplements daily. Additional recommendations were made for breastfed infants. A Canadian survey evaluated the median vitamin D intake derived from diet alone (excluding supplements) among 35,000 Canadians, 10,900 of which were from Ontario. Among Ontarian males ages 9 and up, the median daily dietary vitamin D intake ranged between 196 IU and 272 IU per day. Among females, it varied from 152 IU to 196 IU per day. In boys and girls ages 1 to 3, the median daily dietary vitamin D intake was 248 IU, while among those 4 to 8 years it was 224 IU. VITAMIN D TESTING: Two laboratory tests for vitamin D are available, 25-hydroxy vitamin D, referred to as 25(OH)D, and 1,25-dihydroxyvitamin D. Vitamin D status is assessed by measuring the serum 25(OH)D levels, which can be assayed using radioimmunoassays, competitive protein-binding assays (CPBA), high pressure liquid chromatography (HPLC), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). These may yield different results with inter-assay variation reaching up to 25% (at lower serum levels) and intra-assay variation reaching 10%. The optimal serum concentration of vitamin D has not been established and it may change across different stages of life. Similarly, there is currently no consensus on target serum vitamin D levels. There does, however, appear to be a consensus on the definition of vitamin D deficiency at 25(OH)D < 25 nmol/l, which is based on the risk of diseases such as rickets and osteomalacia. Higher target serum levels have also been proposed based on subclinical endpoints such as parathyroid hormone (PTH). Therefore, in this report, two conservative target serum levels have been adopted, 25 nmol/L (based on the risk of rickets and osteomalacia), and 40 to 50 nmol/L (based on vitamin D's interaction with PTH). ONTARIO CONTEXT: VOLUME #ENTITYSTARTX00026; COST: The volume of vitamin D tests done in Ontario has been increasing over the past 5 years with a steep increase of 169,000 tests in 2007 to more than 393,400 tests in 2008. The number of tests continues to rise with the projected number of tests for 2009 exceeding 731,000. According to the Ontario Schedule of Benefits, the billing cost of each test is $51.7 for 25(OH)D (L606, 100 LMS units, $0.517/unit) and $77.6 for 1,25-dihydroxyvitamin D (L605, 150 LMS units, $0.517/unit). Province wide, the total annual cost of vitamin D testing has increased from approximately $1.7M in 2004 to over $21.0M in 2008. The projected annual cost for 2009 is approximately $38.8M. EVIDENCE-BASED ANALYSIS: The objective of this report is to evaluate the clinical utility of vitamin D testing in the average risk population and in those with kidney disease. As a separate analysis, the report also sought to evaluate the prevalence of vitamin D deficiency in Canada. The specific research questions addressed were thus: What is the clinical utility of vitamin D testing in the average risk population and in subjects with kidney disease?What is the prevalence of vitamin D deficiency in the average risk population in Canada?What is the prevalence of vitamin D deficiency in patients with kidney disease in Canada?Clinical utility was defined as the ability to improve bone health outcomes with the focus on the average risk population (excluding those with osteoporosis) and patients with kidney disease. LITERATURE SEARCH A literature search was performed on July 17th, 2009 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1, 1998 until July 17th, 2009. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist, then a group of epidemiologists until consensus was established. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology. Observational studies that evaluated the prevalence of vitamin D deficiency in Canada in the population of interest were included based on the inclusion and exclusion criteria listed below. The baseline values were used in this report in the case of interventional studies that evaluated the effect of vitamin D intake on serum levels. Studies published in grey literature were included if no studies published in the peer-reviewed literature were identified for specific outcomes or subgroups. Considering that vitamin D status may be affected by factors such as latitude, sun exposure, food fortification, among others, the search focused on prevalence studies published in Canada. In cases where no Canadian prevalence studies were identified, the decision was made to include studies from the United States, given the similar policies in vitamin D food fortification and recommended daily intake. INCLUSION CRITERIA Studies published in EnglishPublications that reported the prevalence of vitamin D deficiency in CanadaStudies that included subjects from the general population or with kidney diseaseStudies in children or adultsStudies published between January 1998 and July 17(th) 2009 EXCLUSION CRITERIA: Studies that included subjects defined according to a specific disease other than kidney diseaseLetters, comments, and editorialsStudies that measured the serum vitamin D levels but did not report the percentage of subjects with serum levels below a given threshold OUTCOMES OF INTEREST Prevalence of serum vitamin D less than 25 nmol/LPrevalence of serum vitamin D less than 40 to 50 nmol/LSerum 25-hydroxyvitamin D was the metabolite used to assess vitamin D status. Results from adult and children studies were reported separately. Subgroup analyses according to factors that affect serum vitamin D levels (e.g., seasonal effects, skin pigmentation, and vitamin D intake) were reported if enough information was provided in the studies QUALITY OF EVIDENCE The quality of the prevalence studies was based on the method of subject recruitment and sampling, possibility of selection bias, and generalizability to the source population. The overall quality of the trials was examined according to the GRADE Working Group criteria. (ABSTRACT TRUNCATED)

Dietary Guidelines for Calcium and Vitamin D: A New Era

Abstract: Ensuring adequate intake of calcium and vitamin D are important nutritional goals for children. They are primarily important for bone growth and development, and recent data suggest the possibility of other important health benefits for these key nutrients throughout life. These new data prompted the Institute of Medicine (IOM) to reevaluate existing dietary recommendations for calcium and vitamin D. On November 30, 2010, the IOM issued a new report that provides dietary recommended intake (DRI) values for calcium and vitamin D for adults and children.1 The final publication of the report will be in 2011; thus, it will be known as the 2011 IOM report. Key pediatric values are shown in Table 1. I was a member of both the previous (1997) and current IOM committees. View this table: TABLE 1 Selected Calcium and Vitamin D DRI Values for Children and Adolescents The previous DRI values provided only adequate intake (AI) values and, in some cases, a tolerable upper intake level (UL) for these key nutrients.2 AI is a single value that would be likely to meet the needs of most children. It is used for infants when either the content of a nutrient in breast milk is the nutritional standard or when limited data are available regarding the average requirements of a population for the nutrient (estimated average requirement [EAR]). Some knowledge or estimate of the variance around the EAR is needed to calculate the recommended dietary allowance (RDA). The better-known RDA is the intake that meets the requirements of nearly all (98%) of the population. Although both values are important in public policy, providers of pediatric care generally advise individual intakes to achieve the RDA to ensure that a child is very likely to meet his or her nutritional needs. In the 2011 report released by the IOM committee, the … Address correspondence to Steven A. Abrams, MD, Baylor College of Medicine, 1100 Bates St, Houston TX 77030. E-mail: sabrams{at}bcm.edu

Patterns of food and nutrient consumption in northern Iran, a high-risk area for esophageal cancer.

Abstract: Our objectives were to investigate patterns of food and nutrient consumption in Golestan province, a high-incidence area for esophageal cancer (EC) in northern Iran Twelve 24-h dietary recalls were administered during a 1-yr period to 131 healthy participants in a pilot cohort study We compare here nutrient intake in Golestan with recommended daily allowances (RDAs) and lowest threshold intakes (LTIs) We also compare the intake of 27 food groups and nutrients among several population subgroups using mean values from the 12 recalls Rural women had a very low level of vitamin intake, which was even lower than LTIs (P < 001) Daily intake of vitamins A and C was lower than LTI in 67% and 73% of rural women, respectively Among rural men, the vitamin intakes were not significantly different from LTIs Among urban women, the vitamin intakes were significantly lower than RDAs but were significantly higher than LTIs Among urban men, the intakes were not significantly different from RDAs Compared to urban dwellers, intake of most food groups and nutrients, including vitamins, was significantly lower among rural dwellers In terms of vitamin intake, no significant difference was observed between Turkmen and non-Turkmen ethnics The severe deficiency in vitamin intake among women and rural dwellers and marked differences in nutrient intake between rural and urban dwellers may contribute to the observed epidemiological pattern of EC in Golestan, with high incidence rates among women and people with low socioeconomic status and the highest incidence rate among rural women