Vitamin D status of clinical practice populations at higher latitudes: analysis and applications

Vitamin D deficiency in elderly: Risk factors and drugs impact on vitamin D status

Introduction:

Vitamin D (VD) deficiency is a major public health problem worldwide. In spite of its high prevalence, particularly among elderly people, VD deficiency is still underestimated by many physicians. Increasingly, VD deficiency is associated with several known geriatric syndromes.

Methods:

The study sample consisted of 125 patients, aged 75 years and older, admitted to the acute geriatric unit. The plausible association between the serum 25-hydroxyvitamin D [25(OH)D] level and patient age, sex, body mass index, renal function, cholecystectomy history, and the prescribed drugs had been investigated. The Fisher's exact test was used to conduct the statistical analysis of data.

Results:

Surprisingly, furosemide treatment was correlated with normal 25(OH)D levels and an increased incidence of secondary hyperparathyroidism. Unlike the other four parameters mentioned above, our data showed that only the patient sex exhibited a significant association with 25(OH)D level as elderly males suffered from a serious VD deficiency as compared to elderly females.

Conclusion:

Old age is an independent risk factor for VD deficiency. The supplementary dose of VD should be precisely defined to achieve the optimal serum 25(OH)D level in elderly people. The definition of the normal serum 25(OH)D threshold in elderly furosemide-treated patients is worth of further studies.

Daily versus stat vitamin D supplementation during pregnancy; A prospective cohort study

BACKGROUND

Despite favorable climatic conditions, vitamin D deficiency (VDD) is widespread in Pakistan. Current study was aimed to evaluate the prevalence of VDD in Pakistani pregnant women and effectiveness of various regimen of Vitamin D supplementation.

METHODOLOGY

This hospital-based prospective cohort study included pregnant women at 12th to 24th weeks of gestation attending Gynae clinic from October 2018 to April 2019. Patients were classified into control and treatment groups (Groups: G1, G2 and G3) according to the dose of vitamin D supplementation. Patients received various regimens of vitamin D including 2000 IU/day (G1), 5000 IU/day (G2) and stat 200000 IU (G3). The levels of vitamin D were measured before and after supplementation. The effectiveness of dosages were compared between and within the groups. Moreover, factors associated with vitamin D sufficiency and insufficiency were ascertained using appropriate statistical methods.

RESULTS

Among 281 pregnant women (mean age: 28.22 ± 4.61 years), VDD was prevalent in 47.3% cases. Vitamin D supplementation caused significant rise in the levels 25(OH)D in treatment groups, while there was no significant difference in control group. The highest mean increment in vitamin D (23.14 ± 11.18 ng/ml) was observed with dose 5000 IU/day followed by doses 200000 IU stat (21.06 ± 13.73 ng/ml) and 2000 IU/day (10.24 ± 5.65 ng/ml). Vitamin D toxicity was observed in one patient who received 200000 IU stat of vitamin D. The frequency of VDD following the supplementation was 5.7%. Education status, duration of sun exposure and use of sunblock was substantially associated with vitamin D sufficiency in the current study.

CONCLUSION

Our findings underscore the high proportion of VDD among pregnant women in Pakistan. Maternal vitamin D supplementation substantially improved the levels of 25(OH)D. Of three used regimens, the dose of 5000 IU/day is considered safe and equally effective as of 200000 IU stat. Since pregnancy is a time of tremendous growth and physiological changes for mother and her developing fetus with lifelong implications for the child, gestational vitamin D supplementation should be considered to ensure the optimal vitamin D accrual in pregnant women. This study generates the hypothesis that vitamin D supplementation at a dose of 5000 IU/day during pregnancy is superior to the other regimens. However, well-controlled randomized trials are needed to confirm these findings.

Traditional foods and 25(OH)D concentrations in a subarctic First Nations community

Background

Sub-optimal vitamin D status is common worldwide and the condition may be associated with increased risk for various chronic diseases. In particular, low vitamin D status is highly prevalent in indigenous communities in Canada, although limited data are available on the determinants of serum 25-hydroxyvitamin D (25(OH)D) concentrations in this population. The relationship between traditional food consumption and vitamin D status has not been well documented.

Objective

To investigate the determinants of serum 25(OH)D status in a First Nations community in Ontario, Canada, with a focus on the role of traditional food consumption and activities.

Methods

A cross-sectional analysis was conducted within the Sandy Lake Health and Diabetes Project (2003–2005). A total of 445 participants (>12 years of age) were assessed for serum 25(OH)D status, anthropometric and lifestyle variables, including traditional and non-traditional dietary practices and activities. Diet patterns were identified using factor analysis, and multivariate linear regression analysis was used to analyse the determinants of 25(OH)D concentrations.

Results

Mean serum 25(OH)D concentrations were 22.1 nmol/L (16.9, 29.9 nmol/L) in men and 20.5 nmol/L (16.0, 27.3 nmol/L) in women. Multivariate determinants of higher serum 25(OH)D included higher consumption of traditional and healthier market foods, higher wild fish consumption, male gender, spring/summer season of blood collection and more frequent physical activity. Significant negative determinants included hours of TV/day, higher BMI and higher consumption of unhealthy market foods.

Conclusions

Traditional food consumption contributed independently to higher 25(OH)D concentrations in a First Nations community with a high prevalence of sub-optimal vitamin D status.

Vitamin D Status, Cardiometabolic, Liver, and Mental Health Status in Obese Youth Attending a Pediatric Weight Management Center

BACKGROUND

Vitamin D (VitD) deficiency and obesity are reaching epidemic proportions in North America, particularly in those with comorbid conditions such as diabetes or liver disease. The study objective was to determine the prevalence of suboptimal vitD status and interrelationships with anthropometric, cardiometabolic, liver, mental health, and lifestyle (sleep/screen time) parameters in an ambulatory population of children with obesity.

METHODS

Children (2-18 years) attending a pediatric weight management clinic (n = 217) were retrospectively reviewed. Variables studied included anthropometric (weight, height, body mass index, waist circumference), vitD (serum 25-hydroxyvitamin D), cardiometabolic (systolic blood pressure, diastolic blood pressure, glucose, insulin, homeostasis model assessment for insulin resistance, triglyceride, high-density lipoprotein, low-density lipoprotein, total cholesterol), liver enzymes (alanine aminotransferase, gamma-glutamyl transferase), and mental health (number, diagnosis) parameters.

RESULTS

Suboptimal vitD status (25-hydroxyvitamin D <75 nmol/L was present in 76% of children with obesity (12.0 ± 2.9 years). Blood pressure categorized as prehypertension, stage I hypertension, and stage II hypertension was present in 14%, 25%, and 7% of children, respectively. Mental health diagnoses including anxiety, attention-deficit hyperactivity disorder, mood disorders, and learning disabilities/developmental delays occurred in 18%, 17%, 10%, and 15%, of children, respectively. Waist circumferences >100 cm were associated with lower vitD levels (58 ± 18 vs 65 ± 17 nmol/L; P = 0.01). VitD status ≥50 nmol/L was associated with lower insulin (15.8 [11.7-23.1] mU/L vs 21.1 [14.3-34.2] mU/L; P < 0.01) and homeostasis model assessment for insulin resistance (3.5 [2.5-4.9] vs 4.8 [3.1-6.9]; P < 0.01) values and systolic blood pressure percentiles (73.0 ± 25.8 vs 80.6 ± 17.0; P = 0.04).

CONCLUSIONS

Children with obesity had a high prevalence of vitD deficiency, particularly those at risk for hypertension, reduced insulin sensitivity, and central obesity.

Diet quality of children post-liver transplantation does not differ from healthy children

Little has been studied regarding the diets of children following LTX. The study aim was to assess and compare dietary intake and DQ of healthy children and children post-LTX. Children and adolescents (2-18 years) post-LTX (n=27) and healthy children (n=28) were studied. Anthropometric and demographic data and two 24-hour recalls (one weekend; one weekday) were collected. Intake of added sugar, HFCS, fructose, GI, and GL was calculated. DQ was measured using three validated DQ indices: the HEI-C, the DGI-CA, and the DQI-I. Although no differences in weight-for-age z-scores were observed between groups, children post-LTX had lower height-for-age z-scores than healthy children (P<.01). With the exception of vitamin B12, no significant differences in energy and macronutrient (protein, carbohydrate, and fat), added sugar, HFCS, fructose, GI, GL, and micronutrient intakes and DQ indices (HEI-C, DGI-CA, and DQI-I) between groups were observed (P>.05). The majority of children in both groups (>40%) had low DQ scores. No significant interrelationships between dietary intake, anthropometric, and demographic were found (P>.05). Both healthy and children post-LTX consume diets with poor DQ. This has implications for risk of obesity and metabolic dysregulation, particularly in transplant populations on immunosuppressive therapies.

Vitamin D and Chronic Diseases

Vitamin D is one of the essential nutrients to sustain the human health. As a member of the steroid hormone family, it has a classic role in regulating metabolism of calcium and a non-classic role in affecting cell proliferation and differentiation. Epidemiological studies have shown that 25OHD deficiency is closely associated with common chronic diseases such as bone metabolic disorders, tumors, cardiovascular diseases, and diabetes. 25OHD deficiency is also a risk factor for neuropsychiatric disorders and autoimmune diseases. 25OHD deficiency is highly prevalent in the world. It is therefore necessary to know the adverse health effects of 25OHD deficiency, and to design interventions and early treatments for those who are likely to have low levels of 25OHD.

Vitamin D Status in South Asian Populations - Risks and Opportunities

Human body acquires a significant amount of vitamin D by cutaneous synthesis under the action of sunlight and less is supplied through nutritional sources. Diversified sociocultural and economic determinants have been identified that limit the dietary intake of vitamin D and enough distribution of sunlight to maintain optimal levels of 25-hydroxyvitamin D (25(OH)D). Consequently, the world has witnessed a high prevalence of hypovitaminosis D in resource-limited South Asian countries. The purpose of this review is to provide a South Asian perspective of vitamin D status, critically examining India, Pakistan, Bangladesh, and Sri Lanka, and to shed light on potential determinants (latitude and season, sunshine exposure habits, age, gender, and genetic factors) leading to hypovitaminosis D among a variety of population groups. Literature search was carried out using bibliographic databases "PubMed," "Google Scholar," and "ScienceDirect.com." Serum 25(OH)D level, 20-50 nmol/L, was mainly taken as vitamin D deficiency, and determinants of low serum 25(OH)D concentration of the population under study were also considered. The review concludes that vitamin D deficiency is highly prevalent among South Asian populations and global efforts are needed to overcome hypovitaminosis in the region. In addition, dietary diversification, supplementation and fortification of foods with vitamin D, adequate exposure to sunlight, and consumption of animal foods were suggested as viable approaches to maintain 25(OH)D levels for optimal health.

Vitamin D3 supplementation, bone health and quality of life in adults with diabetes and chronic kidney disease: Results of an open label randomized clinical trial

BACKGROUND

Adults with diabetes (DM) and chronic kidney disease (CKD) are at risk for vitamin D (vitD) insufficiency, suboptimal bone health and reduced quality of life (QoL) due to limited sunlight exposure, poor vitD intake and CKD.

AIMS

This open-labeled, randomized clinical trial, compared the impact of daily (2000 IU/D) verses monthly (40,000 IU/month) vitD₃ supplementation over six months on markers of vitD status, bone health and QoL in adults with DM and CKD (stages: 1-4).

METHODS

Participants (18-80 years) were randomized to daily (n = 60) or monthly (n = 60) vitD₃ for six months. Primary outcomes included: vitD status (25-hydroxyvitD [25(OH)D], 1, 25-dihydroxyvitD [1,25(OH)₂D], bone health (bone mineral density [BMD] and serum concentrations of bone-specific alkaline phosphatase [BSAP], osteocalcin [OC], N-telopeptide-type 1-collagen [NTx]) and Fibroblast Growth Factor-23 (FGF-23). Secondary outcomes included QoL (Short Form-36 questionnaire).

RESULTS

Adherence by dose allocation over six months was 95.0 ± 5.7% (daily) and 94.1 ± 4.1% (monthly), respectively (p = 0.44); resulting in an overall median [95% CI] increase in serum 25(OH)D of 19 (12-26) nmol/L (p < 0.001). Serum 25(OH)D increased at three (p < 0.001) and six months (p < 0.001) in the daily and monthly groups, respectively. No significant differences over six months between groups were observed in serum concentrations of 1,25(OH)₂D, FGF-23, OC and NTx, BMD and QoL measures (p > 0.05). Serum 25(OH)D ≥ 75 nmol/L was associated with significant reductions in BSAP (p = 0.01) and improved physical functioning vs those with concentrations < 75 nmol/L (62.5 ± 26.8 vs 52.7 ± 26.3; p = 0.03) in the monthly and daily groups, respectively.

CONCLUSIONS

Daily (2000 IU/D) and monthly (40,000 IU/month) vitD₃ supplementation for six months in adults with DM and CKD was safe, and resulted in equivalent adherence and improvements in overall vitD status, but only modest changes in markers of bone health and QoL.

Preconception Care: A New Standard of Care within Maternal Health Services

Emerging research suggests that much pediatric affliction has origins in the vulnerable phase of fetal development. Prenatal factors including deficiency of various nutrients and exposure to assorted toxicants are major etiological determinants of myriad obstetrical complications, pediatric chronic diseases, and perhaps some genetic mutations. With recent recognition that modifiable environmental determinants, rather than genetic predestination, are the etiological source of most chronic illness, modification of environmental factors prior to conception offers the possibility of precluding various mental and physical health conditions. Environmental and lifestyle modification through informed patient choice is possible but evidence confirms that, with little to no training in clinical nutrition, toxicology, or environmental exposures, most clinicians are ill-equipped to counsel patients about this important area. With the totality of available scientific evidence that now exists on the potential to modify disease-causing gestational determinants, failure to take necessary precautionary action may render members of the medical community collectively and individually culpable for preventable illness in children. We advocate for environmental health education of maternity health professionals and the widespread adoption and implementation of preconception care. This will necessitate the translation of emerging knowledge from recent research literature, to health professionals, to reproductive-aged women, and to society at large.

Prevalence of Hypovitaminosis D Among Jordanian Healthy Infants: A Descriptive Cross Sectional Study

To determine vitamin D deficiency and associated risk factors of hypovitaminosis D among Jordanian healthy infants.

DESIGN AND METHODS

A total of 171 infants receiving a routine health check at a Maternal and Child Health Care Center were recruited. Plasma vitamin D 25-OHD level was assessed using a standard analysis of a blood sample. Other data collected included age, gender, birth order, season of birth, and mode of feeding.

RESULTS

Prevalence of vitamin D deficiency (≤15 ng/mL) was 77% (132 out of 171 infants). Infants at risk of vitamin D deficiency were those between 1 to 6 months of age, male, third born or later, born in winter, and exclusively breastfed. The multivariate model showed birth order to be the largest contributor of vitamin D deficiency (R(2)=0.196), followed by breastfed infants (R(2)=0.071), infants born in winter (R(2)=0.037), male gender (R(2)=0.028), and infants aged between 1 and 6 months (R(2)=0.027).

CONCLUSION

Hypovitaminosis D appears to be more common among healthy infants in Jordan. Hypovitaminosis D was found to be common among third or later exclusively breastfeed male infants aged 1 to 6 months who were born during winter.

PRACTICE IMPLICATION

Maternal and child health nurses have a critical role to play in educating mothers about the importance of preventing hypovitaminosis D through adequate sun exposure and ensuring adequate supplementation. A higher dose of vitamin D supplementation for high-risk infants beyond the age of 1 year from developing countries should be administered.

Maternal and Pediatric Health Outcomes in relation to Gestational Vitamin D Sufficiency

Juxtaposed with monumental improvement in maternal-fetal outcomes over the last century, there has been the recent emergence of rising rates of gestational complications including preterm birth, operative delivery, and gestational diabetes. At the same time, there has been a burgeoning problem with widespread vitamin D deficiency among populations of many developed nations. This paper provides a brief review of potential health outcomes recently linked to gestational vitamin D deficiency, including preterm birth, cesarean delivery, and gestational diabetes. Although immediate costs for obstetric complications related to gestational vitamin D insufficiency may be modest, the short- and long-term costs for pediatric healthcare resulting from such gestational complications may be enormous and present an enduring burden on healthcare systems. With increasing evidence pointing to fetal origins of some later life disease, securing vitamin D sufficiency in pregnancy appears to be a simple, safe, and cost-effective measure that can be incorporated into routine preconception and prenatal care in the offices of primary care clinicians. Education on gestational nutritional requirements should be a fundamental part of medical education and residency training, instruction that has been sorely lacking to date.

Vitamin D, Essential Minerals, and Toxic Elements: Exploring Interactions between Nutrients and Toxicants in Clinical Medicine

In clinical medicine, increasing attention is being directed towards the important areas of nutritional biochemistry and toxicant bioaccumulation as they relate to human health and chronic disease. Optimal nutritional status, including healthy levels of vitamin D and essential minerals, is requisite for proper physiological function; conversely, accrual of toxic elements has the potential to impair normal physiology. It is evident that vitamin D intake can facilitate the absorption and assimilation of essential inorganic elements (such as calcium, magnesium, copper, zinc, iron, and selenium) but also the uptake of toxic elements (such as lead, arsenic, aluminum, cobalt, and strontium). Furthermore, sufficiency of essential minerals appears to resist the uptake of toxic metals. This paper explores the literature to determine a suitable clinical approach with regard to vitamin D and essential mineral intake to achieve optimal biological function and to avoid harm in order to prevent and overcome illness. It appears preferable to secure essential mineral status in conjunction with adequate vitamin D, as intake of vitamin D in the absence of mineral sufficiency may result in facilitation of toxic element absorption with potential adverse clinical outcomes.

10 years of mindlines: a systematic review and commentary

Background

In 2004, Gabbay and le May showed that clinicians generally base their decisions on mindlines—internalised and collectively reinforced tacit guidelines—rather than consulting written clinical guidelines. We considered how the concept of mindlines has been taken forward since.

Methods

We searched databases from 2004 to 2014 for the term ‘mindline(s)’ and tracked all sources citing Gabbay and le May’s 2004 article. We read and re-read papers to gain familiarity and developed an interpretive analysis and taxonomy by drawing on the principles of meta-narrative systematic review.

Results

In our synthesis of 340 papers, distinguished between authors who used mindlines purely in name (‘nominal’ view) sometimes dismissing them as a harmful phenomenon, and authors who appeared to have understood the term’s philosophical foundations. The latter took an ‘in-practice’ view (studying how mindlines emerge and spread in real-world settings), a ‘theoretical and philosophical’ view (extending theory) or a ‘solution focused’ view (exploring how to promote and support mindline development). We found that it is not just clinicians who develop mindlines: so do patients, in face-to-face and (potentially) online communities.

Theoretical publications on mindlines have continued to challenge the rationalist assumptions of evidence-based medicine (EBM). Conventional EBM assumes a single, knowable reality and seeks to strip away context to generate universal predictive rules. In contrast, mindlines are predicated on a more fluid, embodied and intersubjective view of knowledge; they accommodate context and acknowledge multiple realities. When considering how knowledge spreads, the concept of mindlines requires us to go beyond the constraining notions of ‘dissemination’ and ‘translation’ to study tacit knowledge and the interactive human processes by which such knowledge is created, enacted and shared. Solution-focused publications described mindline-promoting initiatives such as relationship-building, collaborative learning and thought leadership.

Conclusions

The concept of mindlines challenges the naïve rationalist view of knowledge implicit in some EBM publications, but the term appears to have been misunderstood (and prematurely dismissed) by some authors. By further studying mindlines empirically and theoretically, there is potential to expand EBM’s conceptual toolkit to produce richer forms of ‘evidence-based’ knowledge. We outline a suggested research agenda for achieving this goal.

Electronic supplementary material

The online version of this article (doi:10.1186/s13012-015-0229-x) contains supplementary material, which is available to authorized users.

"Vitamin D supplementation and bone health in adults with diabetic nephropathy: the protocol for a randomized controlled trial"

BACKGROUND

Suboptimal vitamin D status is highly prevalent in Northern communities, particularly in those patients with chronic diseases such as diabetes and chronic renal disease. Emerging literature suggests that adherence to daily vitamin D supplementation may be an important factor influencing vitamin D status and overall bone health, but compliance with therapies for bone health is a major challenge. It is unknown what level of vitamin D supplementation will ameliorate or improve suboptimal vitamin D status in patients with diabetic nephropathy or contribute to improved bone health, particularly for those living in northern climates.

METHODS/DESIGN

The study purpose was to examine two different strategies of vitamin D3 supplementation; daily dosing of 2000 IU per day verses monthly dosing of 40,000 IU per month on markers of vitamin D status, bone health and to examine whether adherence, quality of life and patient satisfaction with the supplementation strategy differs between the two vitamin D strategies in adults diagnosed with diabetic nephropathy.

DISCUSSION

The need for RCTs assessing higher doses of vitamin D3 supplementation at varying frequencies of administration and its impact on bone health in adults with diabetes and chronic kidney disease are needed.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01476501.

International prevalence of indoor tanning: a systematic review and meta-analysis

IMPORTANCE

Indoor tanning is a known carcinogen, but the scope of exposure to this hazard is not known.

OBJECTIVE

To summarize the international prevalence of exposure to indoor tanning.

DATA SOURCES

Studies were identified through systematic searches of PubMed (1966 to present), Scopus (1823 to present), and Web of Science (1898 to present) databases, last performed on March 16, 2013. We also hand searched reference lists to identify records missed by database searches and publicly available data not yet published in the scientific literature.

STUDY SELECTION

Records reporting a prevalence of indoor tanning were eligible for inclusion. We excluded case-control studies, reports with insufficient study information, and reports of groups recruited using factors related to indoor tanning. Two independent investigators performed searches and study selection. Our search yielded 1976 unique records. After exclusions, 161 records were assessed for eligibility in full text, and 88 were included.

DATA EXTRACTION AND SYNTHESIS

Two independent investigators extracted data on characteristics of study participants, inclusion/exclusion criteria, data collection format, outcomes, and statistical methods. Random-effects meta-analyses were used to summarize the prevalence of indoor tanning in different age categories. We calculated the population proportional attributable risk of indoor tanning in the United States, Europe, and Australia for nonmelanoma skin cancer (NMSC) and melanoma.

MAIN OUTCOMES AND MEASURES

Ever and past-year exposure to indoor tanning.

RESULTS

The summary prevalence of ever exposure was 35.7% (95% CI, 27.5%-44.0%) for adults, 55.0% (33.0%-77.1%) for university students, and 19.3% (14.7%-24.0%) for adolescents. The summary prevalence of past-year exposure was 14.0% (95% CI, 11.5%-16.5%) for adults, 43.1% (21.7%-64.5%) for university students, and 18.3% (12.6%-24.0%) for adolescents. These results included data from 406 696 participants. The population proportional attributable risk were 3.0% to 21.8% for NMSC and 2.6% to 9.4% for melanoma, corresponding to more than 450 000 NMSC cases and more than 10 000 melanoma cases each year attributable to indoor tanning in the United States, Europe, and Australia.

CONCLUSIONS AND RELEVANCE

Exposure to indoor tanning is common in Western countries, especially among young persons. Given the large number of skin cancer cases attributable to indoor tanning, these findings highlight a major public health issue.

International prevalence of indoor tanning: a systematic review and meta-analysis

IMPORTANCE

Indoor tanning is a known carcinogen, but the scope of exposure to this hazard is not known.

OBJECTIVE

To summarize the international prevalence of exposure to indoor tanning.

DATA SOURCES

Studies were identified through systematic searches of PubMed (1966 to present), Scopus (1823 to present), and Web of Science (1898 to present) databases, last performed on March 16, 2013. We also hand searched reference lists to identify records missed by database searches and publicly available data not yet published in the scientific literature.

STUDY SELECTION

Records reporting a prevalence of indoor tanning were eligible for inclusion. We excluded case-control studies, reports with insufficient study information, and reports of groups recruited using factors related to indoor tanning. Two independent investigators performed searches and study selection. Our search yielded 1976 unique records. After exclusions, 161 records were assessed for eligibility in full text, and 88 were included.

DATA EXTRACTION AND SYNTHESIS

Two independent investigators extracted data on characteristics of study participants, inclusion/exclusion criteria, data collection format, outcomes, and statistical methods. Random-effects meta-analyses were used to summarize the prevalence of indoor tanning in different age categories. We calculated the population proportional attributable risk of indoor tanning in the United States, Europe, and Australia for nonmelanoma skin cancer (NMSC) and melanoma.

MAIN OUTCOMES AND MEASURES

Ever and past-year exposure to indoor tanning.

RESULTS

The summary prevalence of ever exposure was 35.7% (95% CI, 27.5%-44.0%) for adults, 55.0% (33.0%-77.1%) for university students, and 19.3% (14.7%-24.0%) for adolescents. The summary prevalence of past-year exposure was 14.0% (95% CI, 11.5%-16.5%) for adults, 43.1% (21.7%-64.5%) for university students, and 18.3% (12.6%-24.0%) for adolescents. These results included data from 406 696 participants. The population proportional attributable risk were 3.0% to 21.8% for NMSC and 2.6% to 9.4% for melanoma, corresponding to more than 450 000 NMSC cases and more than 10 000 melanoma cases each year attributable to indoor tanning in the United States, Europe, and Australia.

CONCLUSIONS AND RELEVANCE

Exposure to indoor tanning is common in Western countries, especially among young persons. Given the large number of skin cancer cases attributable to indoor tanning, these findings highlight a major public health issue.

Prevalence of vitamin D insufficiency and associated factors among Canadian Cree: a cross-sectional study

OBJECTIVES

Aboriginal peoples affected by a nutrition transition and living at high latitudes are among the ethnic groups most at risk of vitamin D deficiency. The objectives of this study were to determine the prevalence of meeting predefined cut-off concentrations of vitamin D and to examine associated factors among James Bay Cree aged ≥ 15 years.

METHODS

A cross-sectional study was conducted between the months of May and September from 2005 to 2009. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were determined by radioimmunoassay. Anthropometrics were measured and additional information on socio-demographic characteristics, lifestyle and dietary habits was obtained using questionnaires. A logistic regression model predicting vitamin D insufficiency (<50 nmol/L) included known covariates.

RESULTS

Data were obtained from 944 Cree (406 men (43%); mean age 37.4 years), with an effective participation rate of 49% among women and 41% among men. Mean serum 25(OH)D concentrations (nmol/L) by gender were 52.9 (95% CI 51.4-54.5) in men and 47.5 (95% CI 46.2-48.9) in women, and by age group were 46.0 (95% CI 44.9-48.9) in those 15-39 years and 59.6 (95% CI 57.9-61.4) in those ≥ 40 years of age. Overall, 5.8%, 42.6%, 40.0%, and 11.7% of the participants had 25(OH)D concentrations <30, 30-49.9, 50-74.9 and ≥ 75 nmol/L, respectively. Female gender, obesity, younger age, spring, low fish and milk intake, and low vigorous physical activity predicted vitamin D insufficiency (all p<0.05).

CONCLUSION

The vitamin D status in Eastern James Bay Cree is suboptimal with nearly half of the population having insufficient concentrations for optimum bone health.

Serum 25(OH)D Level and Parathyroid Hormone in Chinese Adult Population: A Cross-Sectional Study in Guiyang Urban Community from Southeast of China

Objective. To evaluate vitamin D status and serum parathyroid hormone (IPTH) of healthy adults living in Guiyang. Design and Participants. We conducted a cross-sectional evaluation in the General Community in Guiyang by cluster sampling method. The data was a part of 1510 participants (634 men, 876 women) aged 20-79 years median 45.2 years from November 2009 to February 2010 in Guiyang Health Measures Survey. Measurements. Aradioimmunoassay was used to measure the level of 25-hydroxyvitamin D [25(OH)D] and intact parathyroid hormone (iPTH). Results.The mean serum 25(OH)D level was (20.4 ± 9.0) ng/mL and the highest level among participants aged 40-59 years (22.8 ng/mL). The mean serum PTH level was (32.1 ± 13.7) pg/mL and the lowest level among participants aged 40-50 years (30.8 ng/mL). Serum 25(OH)D was below 50 nmol/liter in 52.3%, below 75 nmol/liter in 84.6%, and above 75 nmol/liter in 15.4% of the respondents. Secondary hyperparathyroidism was 5.4% (5.4% among men and 4.6% among women). The prevalence of secondary hyperparathyroidism increased (5.8%, 6.5%, and 7.1%, resp.) with decreasing serum 25(OH)D levels among subjects who were 30 to 20, 19.9 to 10, and <10 ng/mL, respectively. Serum 25(OH)D was inversely associated with serum PTH. Conclusions. Vitamin D insufficiency and its complication of secondary hyperparathyroidism are common.

Vitamin D deficiency is a problem for adult out-patients? A university hospital sample in Istanbul, Turkey

OBJECTIVE

To investigate the frequency of vitamin D deficiency in relation to demographics, clinical diagnosis, season of measurement and laboratory parameters in adult out-patients.

DESIGN

Descriptive, retrospective study concerning evaluation of the initial 25-hydroxyvitamin D (25(OH)D) levels determined at admission in relation to demographics, clinical diagnosis, season of measurement and laboratory parameters. 25(OH)D levels ,20 ng/ml were classified as deficiency, 20–30 ng/ml as insufficiency and .30 ng/ml as sufficiency.

SETTING

Out-patient clinics at a tertiary care centre.

SUBJECTS

A total of 2488 adult patients (mean age: 53?3 (SD 15?2) years; 85?2% were females) admitted to out-patient clinics at Baskent University Istanbul Hospital were included.

RESULTS

Mean level of 25(OH)D in the overall population was 17?4 (SD 11?5) ng/ml while insufficiency and deficiency were evident in 24% and 66% of patients, respectively. Mean 25(OH)D levels in males .45 years old were higher than in their female counterparts (19?4 (SD 11?3) ng/ml v. 17?8 (SD 12?2) ng/ml; P,0?05). Mean 25(OH)D levels obtained in summer (18?6 (SD 11?1) ng/ml) and autumn (23?3 (SD 13?6) ng/ml) were significantly higher than levels in spring (16?1 (SD 10?3) ng/ml) and winter (14?6 (SD 10?2) ng/ml; P,0?01). Mean 25(OH)D levels were determined to be significantly lower in obese patients compared with non-obese patients (15?6 (SD 10?4) ng/ml v. 17?6 (SD 11?6) ng/ml; P,0?05). Levels of 25(OH)D were significantly negatively correlated with serum parathyroid hormone levels (r520?194; P,0?001) while significantly positively correlated with phosphorus (r50?059; P,0?01) and HDL cholesterol (r50?070; P,0?01) levels.

CONCLUSIONS

Our findings indicate that vitamin D deficiency is very common among out-patients in Turkey, regardless of gender and age, especially among obese people and during winter and spring.

Combination of Micronutrients for Bone (COMB) Study: bone density after micronutrient intervention

Along with other investigations, patients presenting to an environmental health clinic with various chronic conditions were assessed for bone health status. Individuals with compromised bone strength were educated about skeletal health issues and provided with therapeutic options for potential amelioration of their bone health. Patients who declined pharmacotherapy or who previously experienced failure of drug treatment were offered other options including supplemental micronutrients identified in the medical literature as sometimes having a positive impact on bone mineral density (BMD). After 12 months of consecutive supplemental micronutrient therapy with a combination that included vitamin D(3), vitamin K(2), strontium, magnesium and docosahexaenoic acid (DHA), repeat bone densitometry was performed. The results were analyzed in a group of compliant patients and demonstrate improved BMD in patients classified with normal, osteopenic and osteoporotic bone density. According to the results, this combined micronutrient supplementation regimen appears to be at least as effective as bisphosphonates or strontium ranelate in raising BMD levels in hip, spine, and femoral neck sites. No fractures occurred in the group taking the micronutrient protocol. This micronutrient regimen also appears to show efficacy in individuals where bisphosphonate therapy was previously unsuccessful in maintaining or raising BMD. Prospective clinical trials are required to confirm efficacy.

Vitamin D deficiency among healthy infants and toddlers: a prospective study from Irbid, Jordan

BACKGROUND

The aim of this study was to estimate the prevalence of vitamin D deficiency among healthy infants and toddlers, as well as its associated factors, in Irbid, Jordan.

METHODS

A total of 275 subjects (136 infants and 139 toddlers) aged 6-36 months participated in this study. Information concerning sociodemographic characteristics and early feeding patterns was collected using a self-guided questionnaire. Plasma vitamin D, calcium, phosphorous, and alkaline phosphatase activity were measured.

RESULTS

The prevalence of vitamin D deficiency was 28% (16.7% for severe vitamin D deficiency and 11.3% for vitamin D deficiency) and vitamin D insufficiency was 28.4%. Plasma calcium and alkaline phosphatase levels showed no correlation with the vitamin D status of the study population. For both age groups, a significant association was found between vitamin D status and sun exposure (P < 0.001). A significant association between infant feeding practices and vitamin D status was found (P < 0.001). Infants who were exclusively breast-fed had higher risk for vitamin D deficiency and vitamin D insufficiency than those who were bottle-fed. Multivariate logistic regression analyses results showed that female sex, low sun exposure and exclusive breast-feeding were the main determinants of vitamin D levels.

CONCLUSION

The prevalence of vitamin D deficiency is considered to be high among northern Jordanian infants and toddlers. Sun exposure of less than 30 min daily and exclusively breast-feeding are the main factors for developing vitamin D deficiency.

Worldwide vitamin D status

The aim of the present study is to summarize existing literature on vitamin D levels in adults in different continents and different countries worldwide. The best determinant of vitamin D status is the serum concentration of 25-hydroxyvitamin D (25(OH)D). Most investigators agree that serum 25(OH)D should be higher than 50 nmol/l, but some recommend higher serum levels. Traditional risk groups for vitamin D deficiency include pregnant women, children, older persons, the institutionalized, and non-western immigrants. This chapter shows that serum 25(OH)D levels are not only suboptimal in specific risk groups, but also in adults in many countries. Especially, in the Middle-East and Asia, vitamin D deficiency in adults is highly prevalent.

Asthma prevalence associated with geographical latitude and regional insolation in the United States of America and Australia

BACKGROUND

It has been proposed that vitamin D deficiency may be responsible for an increase in the prevalence of allergic diseases and asthma worldwide. Human ability to generate physiologically required quantities of vitamin D through sun exposure is decreasing with increasing geographical latitude.

OBJECTIVES

Considering that vitamin D deficiency is usually due to lack of outdoor sun exposure, this study is designed to test the hypothesis that a higher prevalence of asthma should be expected at high relative to low geographical latitudes.

METHODS

Linear regression analyses are performed on asthma prevalence in the U.S. adult population vs. geographical latitude, insolation, air temperature, and air pollution (PM(2.5)) for 97 major metropolitan/micropolitan statistical areas of the continental United States of America and on general population asthma prevalence vs. geographical latitude in eight metropolitan areas of Australia.

RESULTS

A 10° change in geographical latitude from southern to northern regions of the Eastern Seaboard is associated with a 2% increase in adult asthma prevalence (p<0.001). Total insolation in winter months is almost as strong as latitude in its ability to explain the observed spatial variation in the prevalence of asthma (r(2) = 0.43; p<0.001). Similar results are obtained using the Australian data (r(2) = 0.73; p<0.01), suggesting a consistent association between the latitude/insolation and asthma prevalence worldwide.

CONCLUSIONS

The results of this study suggest that, as a known modulator of the immune response closely linked with the geographical latitude and erythemal UV irradiation, vitamin D may play an important role in the development/exacerbation of asthma.

Serum 25-hydroxyvitamin D concentrations fluctuate seasonally in young adults of diverse ancestry living in Toronto

Previous research indicates that circulating vitamin D levels are low in many otherwise healthy adults and that there is considerable seasonal variation in 25-hydroxyvitamin D [25(OH)D] concentrations at high latitudes. We examined seasonal variation in 25(OH)D levels in a sample of young adults of diverse ancestry living in the Greater Toronto Area. Three hundred and fifty-one (351) healthy young adults completed both a fall and winter visit during this study. The study was conducted over 2 y (y 1: fall 2007 to winter 2008 and y 2: fall 2008 to winter 2009). At both visits, each participant's serum 25(OH)D concentration was measured. Information was also obtained on skin pigmentation (measured via reflectometer), vitamin D intake, and extent of sun exposure. Overall, the serum 25(OH)D concentration was 54.4 ± 1.3 nmol/L in the fall and 38.4 ± 1.1 nmol/L in the winter. Concentrations differed among ancestral groups at both visits (P < 0.001), with South Asians and East Asians having substantially lower concentrations than Europeans. Skin pigmentation (r(2) = 0.14; P < 0.001), supplemental vitamin D intake (r(2) = 0.09; P < 0.001), sun exposure (r(2) = 0.04; P < 0.001), and study year (r(2) = 0.02; P = 0.017) were predictors of fall 25(OH)D concentrations. During the wintertime, serum 25(OH)D concentrations were associated with concentrations taken in the fall (r(2) = 0.45; P < 0.001), supplemental (r(2) = 0.15; P < 0.001) and dietary vitamin D intake (r(2) = 0.06; P < 0.001), and with study year (r(2) = 0.02; P = 0.009). Our study confirms that serum 25(OH)D concentrations undergo strong seasonal variation at high latitudes and are influenced by vitamin D intake, skin pigmentation, and sun exposure.

A review of the critical role of vitamin D in the functioning of the immune system and the clinical implications of vitamin D deficiency

This review looks at the critical role of vitamin D in improving barrier function, production of antimicrobial peptides including cathelicidin and some defensins, and immune modulation. The function of vitamin D in the innate immune system and in the epithelial cells of the oral cavity, lung, gastrointestinal system, genito-urinary system, skin and surface of the eye is discussed. Clinical conditions are reviewed where vitamin D may play a role in the prevention of infections or where it may be used as primary or adjuvant treatment for viral, bacterial and fungal infections. Several conditions such as tuberculosis, psoriasis, eczema, Crohn's disease, chest infections, wound infections, influenza, urinary tract infections, eye infections and wound healing may benefit from adequate circulating 25(OH)D as substrate. Clinical diseases are presented in which optimization of 25(OH)D levels may benefit or cause harm according to present day knowledge. The safety of using larger doses of vitamin D in various clinical settings is discussed.

Evolution in pediatric health care

BACKGROUND

There is disturbing evidence of escalating chronic disease among children--a phenomenon that is extracting a heavy toll from individuals, families, and health-care systems.

METHODS

This review was prepared by assessing medical and scientific literature available from Medline, as well as by reviewing numerous books, conference proceedings, and government publications.

RESULTS

Knowledge translation in medical science, the process whereby new research is incorporated into clinical practice, remains lethargic. Nutritional and environmental factors have recently been recognized as common determinants of modern illness, and various diagnostic techniques in molecular medicine are now available to facilitate diagnosis of disease etiology.

CONCLUSIONS

A re-evaluation of the current pediatric clinical paradigm is required in light of emerging research from fields such as epigenetics, molecular medicine and environmental health. Education about these branches of medical science should be integrated into pediatric medical education, and important research information from these disciplines should be incorporated into public health care and clinical practice relating to children.

Addressing vitamin D deficiency in Canada: a public health innovation whose time has come

There is disturbing evidence of widespread vitamin D deficiency in many population groups, particularly within nations at high latitude. Numerous recent studies in the scientific literature associate vitamin D deficiency with a colossal increase in morbidity and mortality. Since Canada is at higher latitude, this review assesses the vitamin D status within the Canadian population. This review was prepared by assessing available medical and scientific literature from Medline, as well as by reviewing several books and conference proceedings. A standard 25(OH)D level of 75-80nmol/l or more was used to indicate vitamin D sufficiency. Between 70% and 97% of Canadians demonstrate vitamin D insufficiency. Furthermore, studies assessing 25(OH)D levels of vitamin D at 25-40nmol/l reveal that many Canadians have profoundly deficient levels. Repletion of vitamin D3 with 2000IU/day for those not receiving judicious sun exposure and those with no contra-indications would likely achieve normalized levels in more than 93% of patients, without risk of toxicity. Explicit directives regarding vitamin D assessment and management are urgently required.

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

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)

Celiac disease presenting as autism

Gluten-restricted diets have become increasingly popular among parents seeking treatment for children diagnosed with autism. Some of the reported response to celiac diets in children with autism may be related to amelioration of nutritional deficiency resulting from undiagnosed gluten sensitivity and consequent malabsorption. A case is presented of a 5-year-old boy diagnosed with severe autism at a specialty clinic for autistic spectrum disorders. After initial investigation suggested underlying celiac disease and varied nutrient deficiencies, a gluten-free diet was instituted along with dietary and supplemental measures to secure nutritional sufficiency. The patient's gastrointestinal symptoms rapidly resolved, and signs and symptoms suggestive of autism progressively abated. This case is an example of a common malabsorption syndrome associated with central nervous system dysfunction and suggests that in some contexts, nutritional deficiency may be a determinant of developmental delay. It is recommended that all children with neurodevelopmental problems be assessed for nutritional deficiency and malabsorption syndromes.