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Cleveland Clinic Journal of Medicine Mar 2020Megaloblastic anemia causes macrocytic anemia from ineffective red blood cell production and intramedullary hemolysis. The most common causes are folate (vitamin B)... (Review)
Review
Megaloblastic anemia causes macrocytic anemia from ineffective red blood cell production and intramedullary hemolysis. The most common causes are folate (vitamin B) deficiency and cobalamin (vitamin B) deficiency. Megaloblastic anemia can be diagnosed based on characteristic morphologic and laboratory findings. However, other benign and neoplastic diseases need to be considered, particularly in severe cases. Therapy involves treating the underlying cause-eg, with vitamin supplementation in cases of deficiency, or with discontinuation of a suspected medication.
Topics: Adolescent; Aged; Anemia, Megaloblastic; Avitaminosis; Diagnosis, Differential; Dietary Supplements; Female; Folic Acid; Folic Acid Deficiency; Humans; Male; Severity of Illness Index; Vitamin B 12; Vitamin B 12 Deficiency
PubMed: 32127439
DOI: 10.3949/ccjm.87a.19072 -
Endocrine Reviews Aug 2019The etiology of endemic rickets was discovered a century ago. Vitamin D is the precursor of 25-hydroxyvitamin D and other metabolites, including 1,25(OH)2D, the ligand... (Review)
Review
The etiology of endemic rickets was discovered a century ago. Vitamin D is the precursor of 25-hydroxyvitamin D and other metabolites, including 1,25(OH)2D, the ligand for the vitamin D receptor (VDR). The effects of the vitamin D endocrine system on bone and its growth plate are primarily indirect and mediated by its effect on intestinal calcium transport and serum calcium and phosphate homeostasis. Rickets and osteomalacia can be prevented by daily supplements of 400 IU of vitamin D. Vitamin D deficiency (serum 25-hydroxyvitamin D <50 nmol/L) accelerates bone turnover, bone loss, and osteoporotic fractures. These risks can be reduced by 800 IU of vitamin D together with an appropriate calcium intake, given to institutionalized or vitamin D-deficient elderly subjects. VDR and vitamin D metabolic enzymes are widely expressed. Numerous genetic, molecular, cellular, and animal studies strongly suggest that vitamin D signaling has many extraskeletal effects. These include regulation of cell proliferation, immune and muscle function, skin differentiation, and reproduction, as well as vascular and metabolic properties. From observational studies in human subjects, poor vitamin D status is associated with nearly all diseases predicted by these extraskeletal actions. Results of randomized controlled trials and Mendelian randomization studies are supportive of vitamin D supplementation in reducing the incidence of some diseases, but, globally, conclusions are mixed. These findings point to a need for continued ongoing and future basic and clinical studies to better define whether vitamin D status can be optimized to improve many aspects of human health. Vitamin D deficiency enhances the risk of osteoporotic fractures and is associated with many diseases. We review what is established and what is plausible regarding the health effects of vitamin D.
Topics: Animals; Bone and Bones; Calcium; Female; Humans; Male; Osteomalacia; Rickets; Signal Transduction; Vitamin D; Vitamin D Deficiency
PubMed: 30321335
DOI: 10.1210/er.2018-00126 -
Annals of the New York Academy of... Aug 2021Thiamine is an essential water-soluble vitamin that plays an important role in energy metabolism. Thiamine deficiency presents many challenges to clinicians, in part due... (Review)
Review
Thiamine is an essential water-soluble vitamin that plays an important role in energy metabolism. Thiamine deficiency presents many challenges to clinicians, in part due to the broad clinical spectrum, referred to as thiamine deficiency disorders (TDDs), affecting the metabolic, neurologic, cardiovascular, respiratory, gastrointestinal, and musculoskeletal systems. Concurrent illnesses and overlapping signs and symptoms with other disorders can further complicate this. As such, TDDs are frequently misdiagnosed and treatment opportunities missed, with fatal consequences or permanent neurologic sequelae. In the absence of specific diagnostic tests, a low threshold of clinical suspicion and early therapeutic thiamine is currently the best approach. Even in severe cases, rapid clinical improvement can occur within hours or days, with neurological involvement possibly requiring higher doses and a longer recovery time. Active research aims to help better identify patients with thiamine-responsive disorders and future research is needed to determine effective dosing regimens for the various clinical presentations of TDDs. Understanding the clinical diagnosis and global burden of thiamine deficiency will help to implement national surveillance and population-level prevention programs, with education to sensitize clinicians to TDDs. With concerted effort, the morbidity and mortality related to thiamine deficiency can be reduced.
Topics: Age Factors; Beriberi; Combined Modality Therapy; Diagnosis, Differential; Disease Management; Disease Transmission, Infectious; Humans; Organ Specificity; Population Surveillance; Symptom Assessment; Thiamine; Thiamine Deficiency
PubMed: 33305487
DOI: 10.1111/nyas.14536 -
Mayo Clinic Proceedings Aug 2010Recent evidence for the nonskeletal effects of vitamin D, coupled with recognition that vitamin D deficiency is common, has revived interest in this hormone. Vitamin D... (Review)
Review
Recent evidence for the nonskeletal effects of vitamin D, coupled with recognition that vitamin D deficiency is common, has revived interest in this hormone. Vitamin D is produced by skin exposed to ultraviolet B radiation or obtained from dietary sources, including supplements. Persons commonly at risk for vitamin D deficiency include those with inadequate sun exposure, limited oral intake, or impaired intestinal absorption. Vitamin D adequacy is best determined by measurement of the 25-hydroxyvitamin D concentration in the blood. Average daily vitamin D intake in the population at large and current dietary reference intake values are often inadequate to maintain optimal vitamin D levels. Clinicians may recommend supplementation but be unsure how to choose the optimal dose and type of vitamin D and how to use testing to monitor therapy. This review outlines strategies to prevent, diagnose, and treat vitamin D deficiency in adults.
Topics: Adult; Humans; Vitamin D Deficiency
PubMed: 20675513
DOI: 10.4065/mcp.2010.0138 -
Nutrients Apr 2022Vitamin D deficiency has a high worldwide prevalence, but actions to improve this public health problem are challenged by the heterogeneity of nutritional and clinical... (Review)
Review
Vitamin D deficiency has a high worldwide prevalence, but actions to improve this public health problem are challenged by the heterogeneity of nutritional and clinical vitamin D guidelines, with respect to the diagnosis and treatment of vitamin D deficiency. We aimed to address this issue by providing respective recommendations for adults, developed by a European expert panel, using the Delphi method to reach consensus. Increasing the awareness of vitamin D deficiency and efforts to harmonize vitamin D guidelines should be pursued. We argue against a general screening for vitamin D deficiency but suggest 25-hydroxyvitamin D (25(OH)D) testing in certain risk groups. We recommend a vitamin D supplementation dose of 800 to 2000 international units (IU) per day for adults who want to ensure a sufficient vitamin D status. These doses are also recommended for the treatment of vitamin D deficiency, but higher vitamin D doses (e.g., 6000 IU per day) may be used for the first 4 to 12 weeks of treatment if a rapid correction of vitamin D deficiency is clinically indicated before continuing, with a maintenance dose of 800 to 2000 IU per day. Treatment success may be evaluated after at least 6 to 12 weeks in certain risk groups (e.g., patients with malabsorption syndromes) by measurement of serum 25(OH)D, with the aim to target concentrations of 30 to 50 ng/mL (75 to 125 nmol/L).
Topics: Adult; Cholecalciferol; Dietary Supplements; Humans; Prevalence; Risk Factors; Vitamin D; Vitamin D Deficiency; Vitamins
PubMed: 35406098
DOI: 10.3390/nu14071483 -
Blood May 2017B deficiency is the leading cause of megaloblastic anemia, and although more common in the elderly, can occur at any age. Clinical disease caused by B deficiency usually... (Review)
Review
B deficiency is the leading cause of megaloblastic anemia, and although more common in the elderly, can occur at any age. Clinical disease caused by B deficiency usually connotes severe deficiency, resulting from a failure of the gastric or ileal phase of physiological B absorption, best exemplified by the autoimmune disease pernicious anemia. There are many other causes of B deficiency, which range from severe to mild. Mild deficiency usually results from failure to render food B bioavailable or from dietary inadequacy. Although rarely resulting in megaloblastic anemia, mild deficiency may be associated with neurocognitive and other consequences. B deficiency is best diagnosed using a combination of tests because none alone is completely reliable. The features of B deficiency are variable and may be atypical. Timely diagnosis is important, and treatment is gratifying. Failure to diagnose B deficiency can have dire consequences, usually neurological. This review is written from the perspective of a practicing hematologist.
Topics: Anemia, Megaloblastic; Anemia, Pernicious; Animals; Folic Acid; Humans; Intestinal Absorption; Vitamin B 12; Vitamin B 12 Deficiency
PubMed: 28360040
DOI: 10.1182/blood-2016-10-569186 -
Archivos Argentinos de Pediatria Feb 2018Vitamin D research suggests it has a role in disorders other than bone metabolism. (Review)
Review
INTRODUCTION
Vitamin D research suggests it has a role in disorders other than bone metabolism.
OBJECTIVE
To update the information on vitamin D deficiency (VDD) in pediatric clinical disorders.
METHODS
Search in virtual libraries, giving priority to clinical and longitudinal studies and meta-analyses on VDD in the pediatric age group published in the past 20 years. The terms "vitamin D deficiency", "children and adolescents" (both in Spanish and English) were used as search descriptors.
RESULTS
In the pediatric population, VDD is associated with different clinical diseases, such as bone alterations, insulin resistance, metabolic syndrome, respiratory tract infections, asthma, and autoimmune diseases. Besides, it is associated with prematurity, obesity, malabsorption, use of anticonvulsant agents, and lifestyle characteristics, such as clothing, extreme latitudes, low consumption, and little sun exposure.
CONCLUSIONS
According to the evidence, VDD is highly prevalent in several disorders and diseases in the pediatric age group. The recommendation is to prevent VDD in risk conditions and to maintain 25(OH)D serum levels > 75 nmol/L.
Topics: Adolescent; Child; Child, Preschool; Humans; Vitamin D Deficiency
PubMed: 29333826
DOI: 10.5546/aap.2018.eng.e75 -
Indian Pediatrics Feb 2022The emerging literature on prevalence of vitamin D deficiency in India, prevention and treatment strategies of rickets, and extra-skeletal benefits of vitamin D suggest...
JUSTIFICATION
The emerging literature on prevalence of vitamin D deficiency in India, prevention and treatment strategies of rickets, and extra-skeletal benefits of vitamin D suggest the need for revising the existing guidelines for prevention and treatment of vitamin D deficiency in India.
OBJECTIVES
To review the emerging literature on vitamin D prevalence and need for universal vitamin D supplementation. To suggest optimum vitamin D therapy for treatment of asymptomatic and symptomatic vitamin D deficiency, and rickets. To evaluate the extra-skeletal health benefits of vitamin D in children.
PROCESS
A National consultative committee was formed that comprised of clinicians, epidemiologists, endocrinologists, and nutritionists. The Committee conducted deliberations on different aspects of vitamin D deficiency and rickets through ten online meetings between March and September, 2021. A draft guideline was formulated, which was reviewed and approved by all Committee members.
RECOMMENDATIONS
The group reiterates the serum 25-hydroxy vitamin D cutoffs proposed for vitamin D deficiency, insufficiency, and sufficiency as <12 ng/mL, 12-20 ng/mL and >20 ng/mL, respectively. Vitamin D toxicity is defined as serum 25OHD >100 ng/mL with hypercalcemia and/or hypercalciuria. Vitamin D supplementation in doses of 400 IU/day is recommended during infancy; however, the estimated average requirement in older children and adolescents (400-600 IU/day, respectively) should be met from diet and natural sources like sunlight. Rickets and vitamin D deficiency should be treated with oral cholecalciferol, preferably in a daily dosing schedule (2000 IU below 1 year of age and 3000 IU in older children) for 12 weeks. If compliance to daily dosing cannot be ensured, intermittent regimens may be prescribed for children above 6 months of age. Universal vitamin D supplementation is not recommended in childhood pneumonia, diarrhea, tuberculosis, HIV and non-infectious conditions like asthma, atopic dermatitis, and developmental disorders. Serum 25-hydroxy vitamin D level of >20 ng/mL should be maintained in children with conditions at high-risk for vitamin deficiency, like nephrotic syndrome, chronic liver disease, chronic renal failure, and intake of anticonvulsants or glucocorticoids.
Topics: Adolescent; Child; Cholecalciferol; Dietary Supplements; Humans; Pediatrics; Rickets; Vitamin D; Vitamin D Deficiency; Vitamins
PubMed: 34969941
DOI: No ID Found -
Journal of Nutritional Science Jun 2020The vitamin status of a child depends on many factors and most of the clinical studies do not take into account the different access to adequate nutrition of children... (Review)
Review
The vitamin status of a child depends on many factors and most of the clinical studies do not take into account the different access to adequate nutrition of children coming from different countries and the consequent major differences in micronutrients or vitamin deficits between low-income and high-income countries. Vitamin supplements are included in the general field of dietary supplements. There is a large amount of not always factual material concerning vitamin supplements, and this may sometimes create confusion in clinicians and patients. Inadequate information may lead to the risk of attributing beneficial properties leading to their over-use or misuse in the paediatric field. Vitamin supplementation is indicated in all those conditions in which a vitamin deficiency is found, either because of a reduced intake due to reduced availability of certain foods, restrictive diets or inadequate absorption. The lack of guidelines in these fields may lead paediatricians to an improper use of vitamins, both in terms of excessive use or inadequate use. This is due to the fact that vitamin supplementation is often intended as a therapy of support rather than an essential therapeutic tool able to modify disease prognosis. In fact, various vitamins and their derivatives have therapeutic potential in the prevention and treatment of many diseases, especially in emerging conditions of paediatric age such as type 2 diabetes and the metabolic syndrome. The aim of the present article is to analyse the state of the art and consider new perspectives on the role of vitamin supplements in children.
Topics: Ascorbic Acid; Avitaminosis; Child; Databases, Factual; Diabetes Mellitus, Type 2; Dietary Supplements; Folic Acid; Humans; Micronutrients; Nutritional Status; Vitamin A; Vitamin B 12; Vitamin D; Vitamin E; Vitamins
PubMed: 32577225
DOI: 10.1017/jns.2020.12 -
Gastroenterology Clinics of North... Dec 2017Indiscriminate use of multivitamin/mineral supplements in the general population may be misguided, but patients with chronic Inflammatory Bowel Diseases (IBD) should be... (Review)
Review
Indiscriminate use of multivitamin/mineral supplements in the general population may be misguided, but patients with chronic Inflammatory Bowel Diseases (IBD) should be monitored and compensated for nutritional deficiencies. Mechanistic links between vitamin/mineral deficiencies and IBD pathology has been found for some micronutrients and normalizing their levels is clinically beneficial. Others, like vitamin A, although instinctively desirable, produced disappointing results. Restoring normal levels of the selected micronutrients requires elevated doses to compensate for defects in absorptive or signaling mechanisms. This article describes some aspects of vitamin and mineral deficiencies in IBD, and summarizes pros and cons of supplementation.
Topics: Anemia, Iron-Deficiency; Animals; Avitaminosis; Biotin; Calcium; Cholecalciferol; Dietary Supplements; Folic Acid; Humans; Inflammatory Bowel Diseases; Iron; Thiamine; Vitamin A; Vitamin B 12; Vitamin B 6; Vitamin K; Vitamins; Zinc
PubMed: 29173522
DOI: 10.1016/j.gtc.2017.08.011