Global Health Disparities in Childhood Rickets.

Nutritional rickets is a global health problem reflecting both historical and contemporary health disparities arising from racial, ethnic, environmental, and geopolitical circumstances. It primarily affects marginalized populations and can contribute to long-term morbidity. Deficits in bone health in childhood may also contribute to osteomalacia/osteoporosis. Solutions require a global public health approach.

Nutritional rickets in Turkish and refugee children aged 0-2: an increasing problem despite vitamin D prophylaxis.

BACKGROUND: Nutritional rickets (NR) is still a major problem and is exacerbated by an increasing influx of immigrants. In this study, Turkish and immigrant cases followed with the diagnosis of NR in our pediatric endocrinology clinic were retrospectively evaluated. METHODS: Detailed data of cases diagnosed with NR between 2013 and 2020 and followed for at least six months were reviewed. RESULTS: In the study period, 77 cases of NR were identified. Turkish children constituted 76.6% (n=59) while 18 (23.4%) were immigrant children. The mean age at diagnosis was 8.1±7.8 months, 32.5% (n=25) were female, and 67.5% (n=52) were male. The 25-hydroxyvitamin D3 was below normal in all patients, with a mean value of 4.3±2.6 ng/mL. Parathyroid hormone (PTH) was above normal in all and the mean value was 301.7±139.3 pg/ mL. While there were 3.9 cases of NR in 10,000 endocrine clinic patients in 2013, this rate increased more than four-fold to 15.7 patients in 2019. CONCLUSIONS: Despite the vitamin D prophylaxis program in Türkiye, NR is seen significantly more frequently in recent years, which may be associated with an increasing number of refugees. High PTH levels indicate the severity of NR cases admitted to our clinic. However, clinically significant NR is only the tip of the iceberg and the true burden of subclinical rickets is unknown. Increasing compliance with the vitamin D supplementation program in refugee and Turkish children is important for the prevention of nutritional rickets.

Prevalence of hypovitaminosis D among children and adolescents of Kabul: a descriptive cross-sectional study.

BACKGROUND: Vitamin D is one of the most important fat-soluble vitamins necessary for normal growth and development of the human body. According to a study done in Kabul shows that economic, racial, and social concerns are thought to be the main impediments to receiving appropriate amounts of this vitamin through dietary sources in countries like Afghanistan. Hypovitaminosis D, on the other hand, is now recognized as a pandemic in both industrialized and developing countries. METHODS: To find out how common hypovitaminosis D is in children aged one month to eighteen years in afghan children Kabul, Afghanistan. Vitamin D deficiency and insufficiency are defined as serum levels of less than 20 ng/mL and 20 to 30 ng/mL, respectively. Children aged between 1 month to 18 years attending our hospital, AMC (Ariana Medical Complex) for health examination were checked for their 25-hydroxyvitamin D [25(OH)D]. Age, gender and address were recorded. 25(OH)D were determined using immunoassay auto analyzers. According to their serum 25(OH)D, the 25(OH)D were categorized into five categories: sufficiency: ≥ 30-100 ng/mL; insufficiency: ≥ 20-29 ng/mL; deficiency: < 20 ng/mL; severe deficiency: < 10 ng/mL; and intoxication: > 150 ng/mL. Participants who were intoxicated with vitamin D were excluded from the study. RESULTS: A total of 4008 children aged 1 month to 18 years participated in this cross-sectional study. Hypovitaminosis D was found to be prevalent in 62.5 percent of the population. When compared to boys, female children were 1.2 times more likely to be vitamin D deficient. When compared to children of illiterate women, the odds of hypovitaminosis D were 1.4, 1.9, and 5.8 times lower in children with mothers educated up to primary school, graduation, and post-graduate. The average vitamin D level was 23 ng/mL, with a median of 15 ng/mL and maximum and minimum values of 135 ng/mL and 3 ng/mL, respectively. In all, 2500 (62.5%) of the children had low levels of vitamin D in their serum. Only 400 (16%) of the patients were sufficient, whereas 917 (36.7%) were severely deficient, 733 (29.3%) were deficient, and 450 (18%) were insufficient. With a female to male ratio of 1.2:1, the majority of those, 1335 (53.4%), were females and 1165 (46.6%) were males. Patients were 8.14 years old on average, with a median age of 7 years. The majority of the patients, 2152 (86.1%), were urban, while 348 (13.9%) were rural. CONCLUSION: The prevalence of hypovitaminosis D was very high in Afghan children. Female sex, higher socio economic status, higher educational status of the mother and living at urban areas were the factors with strong positive association with hypovitaminosis D.

Impact of a Prenatal Vitamin D Supplementation Program on Vitamin D Deficiency, Rickets and Early Childhood Caries in an Alaska Native Population.

Background: Early childhood rickets increased in Alaska Native children after decreases in vitamin D-rich subsistence diet in childbearing-aged women. We evaluated the impact of routine prenatal vitamin D supplementation initiated in Alaska's Yukon Kuskokwim Delta in Fall 2016. Methods: We queried electronic health records of prenatal women with 25(OH) vitamin D testing during the period 2015−2019. We evaluated 25(OH)D concentrations, vitamin D3 supplement refills, and decayed, missing, and filled teeth (dmft) scores and rickets in offspring. Results: Mean 25(OH)D concentrations increased 36.5% from pre- to post-supplementation; the percentage with deficient 25(OH)D decreased by 66.4%. Women with ≥ 60 vitamin D3 refill days had higher late pregnancy 25(OH)D concentrations than those with no refill days (p < 0.0001). Women with late pregnancy insufficient 25(OH)D concentrations had offspring with higher dmft scores than those with sufficient 25(OH)D (RR 1.3, p < 0.0001). Three children were diagnosed with nutritional rickets during the period 2001−2021, and none after 2017. Conclusions: These findings suggest that prenatal vitamin D supplementation can improve childhood outcomes in high-risk populations with high rates of rickets.

The Development of Rickets in Children and Nursing Contributions to Treatment.

Rickets is one of the most prevalent non-communicable diseases in children in the developing world. It is often found in cultures in which children follow strict vegetarian diets and are not exposed to vitamin D-enhanced foods. While a rare occurrence, X-linked hypophosphatemic rickets may be the most frequent type of the disease seen outside the Third World today. However, there is not much credible information on the extent of the development of rickets. Therefore, pediatric nurses must be able to recognize children at risk and provide best practice care for the prevention and treatment of rickets. When caring for children in hospitals, communities or classrooms, nurses play a vital role in identifying children at risk for hypovitaminosis D and advising families to, if possible, follow safe diets and take supplements in order to avoid health complications associated with low levels of vitamin D. This study examines the prevalence and variables contributing to rickets, including hypovitaminosis vitamin D, the consequent orthopedic problems and the role of nurses in preventing and managing the pathogenesis of rickets and ultimately avoiding extreme deficits that result in bone deformities and the need for corrective surgery.

A major health problem facing immigrant children: nutritional rickets.

OBJECTIVES: Nutritional rickets (NR) is still an important problem and one which increasing influxes of immigrants are further exacerbating. This study evaluated cases of mostly immigrant children followed up with diagnoses of NR in our pediatric endocrinology clinic. METHODS: Details of 20 cases diagnosed with NR between 2017 and 2020 were retrieved from file records. RESULTS: Twenty (11 male) cases were included in the study. Three (15%) were Turkish nationals and the others (85%) were immigrants. Hypocalcemia and hypophosphatemia were detected in 17 and 13, respectively. Alkaline phosphatase (ALP) values were normal in two cases, while ALP and parathyroid hormone (PTH) values were elevated in all other cases, and PTH levels were very high (473.64 ± 197.05 pg/mL). 25-hydroxyvitamin D levels were below 20 ng/mL in all cases. Patients with NR received high-dose long-term vitamin D or stoss therapy. Six patients failed to attend long-term follow-up, while PTH and ALP levels and clinical findings improved at long-term follow-up in the other 14 cases. CONCLUSIONS: The elevated PTH levels suggest only the most severe cases of NR presented to our clinic. Clinically evident NR is therefore only the tip of the iceberg, and the true burden of subclinical rickets and osteomalacia remains unidentified. Public health policies should therefore focus on universal vitamin D supplementation and adequate dietary calcium provision, their integration into child surveillance programs, adequate advice and support to ensure normal nutrition, exposure to sunlight, and informing families of the increased risk not only for resident populations but also for refugee and immigrant children.

Rickets Due to Severe Vitamin D and Calcium Deficiency During the COVID-19 Pandemic in Malaysia.

BACKGROUND Rickets is the deficiency in mineralization of the bone associated with lack of sunlight exposure and inadequate dietary calcium and/or vitamin D in children. Important efforts to eradicate rickets include appropriate sunlight exposure advice and fortification of food and milk with vitamin D. However, there is a growing concern that the current Coronavirus Disease 2019 (COVID-19) pandemic will increase the incidence of rickets due to inadequate sunlight exposure resulting from movement restriction measures imposed by governments across the world. CASE REPORT A 22-month-old girl presented to our primary care clinic in Selangor, Malaysia with abnormal gait and bowing of the legs during the COVID-19 pandemic. She had a history of inadequate sun exposure as she lived in an apartment and there was a Movement Control Order in place because of the pandemic. Calcium intake was also poor as she could not tolerate formula milk and did not consume any other dairy products. Investigations revealed severe hypocalcemia and low vitamin D level. She was diagnosed with nutritional rickets and was referred for admission to correct the hypocalcemia. She was subsequently discharged with oral calcium and vitamin D supplementation. Her calcium and vitamin D levels improved and at her 6-month review, her bilateral bowed legs had improved significantly. CONCLUSIONS This case highlights the importance of having a high degree of suspicion for vitamin D deficiency and rickets in young children growing up during the COVID-19 pandemic. Public health messages on preventing the spread of COVID-19 should also be interlaced with messages addressing the possible effects of our new norms such as inadequate sunlight exposure.

Vitamin D deficiency, supplementation and testing: have we got it right in New Zealand?

BACKGROUND: Severe prolonged vitamin D deficiency can cause rickets or osteomalacia. Both can be prevented by sunshine exposure or vitamin D supplementation. Although New Zealand guidance does not recommend vitamin D supplementation for the general population, it can be considered for individuals at risk of vitamin D deficiency. Routine measurement of 25-hydroxyvitamin D (25OHD) is also considered unnecessary. METHODS: We investigated the rates of vitamin D supplementation, rickets and osteomalacia in New Zealand, and of 25OHD results in Auckland, over the last two decades. RESULTS: Vitamin D prescriptions increased 14-fold, from 86,295/year to 1,215,507/year, between 2003 and 2019, with medication costs alone in 2019 being >$1 million. Despite these changes, the annual prevalence of hospital admissions for rickets, osteomalacia and unspecified vitamin D deficiency remained low and stable (10-20/year). 25OHD concentrations increased between 2002 and 2003 and between 2009 and 2019, and in the later time-period, 25OHD tests mainly identified individuals without vitamin D deficiency (40-50% >75nmol/L, 65-70% >50nmol/L and only 7-12.5% <25nmol/L). CONCLUSIONS: Osteomalacia and rickets persist at low rates despite widespread, increasingly costly vitamin D supplementation and testing, which largely identifies individuals without vitamin D deficiency. These results suggest that vitamin D guidance and practice in New Zealand should change.

Can the palaeoepidemiology of rickets during the industrialisation period in France be studied through bioarchaeological grey literature and French medico-historical literature of the 18th-early 20th centuries? Preliminary examination of a complex topic.

OBJECTIVE: This study explores whether data relating to rickets from the French medico-historical literature (FMHL) and bioarchaeological grey literature are useful in evaluating its epidemiology during the industrialisation of France. Unlike other European countries such as England, industrialisation in France was a slow and continuous process with two phases: the first in 1830-1870 and the second in 1870-1914. MATERIALS AND METHODS: A bibliographical analysis of 2800 FMHL sources from the 18th to the early 20th centuries and 50 archaeological excavation reports from the last 21 years was undertaken. RESULTS: The FMHL data is very heterogeneous and predominantly dates to the second phase of industrialisation. The bioarchaeological data is very incomplete and predominantly relates to the period before industrialisation. At the same time, knowledge improvement and institutional changes to protect children could explain more systematic registration of cases of rickets. CONCLUSIONS: No solid conclusions can be made regarding the prevalence of rickets at present, however these data hold great potential. SIGNIFICANCE: In comparison to England, no systematic investigation of rickets prevalence during the period of industrialisation in France has been undertaken to date. LIMITATIONS: The lack of archaeological excavations from this period and the limited paleopathological analysis of the sites excavated have contributed to our current lack of understanding regarding the impact of industrialization on the prevalence of rickets on the French population. SUGGESTIONS FOR FURTHER WORK: The FMHL data needs to be homogenized and osteoarchaeological collections need to be restudied with a common protocol focusing on signs of vitamin D deficiency.

Hypovitaminosis D in migrant children in Switzerland: a retrospective study.

Cholecalciferol (vitamin D3) is essentially known for its role in the phosphocalcic metabolism and its associated pathologies, such as rickets. In Switzerland, 35 to 50% of children are vitamin D deficient. Due to skin colour, poor nutrition, living conditions and cultural practices, migrant population is particularly at risk. Our aim is to attest the prevalence of hypovitaminosis D in children arriving in Switzerland. We retrospectively assessed 528 children's vitamin D status and parathyroid hormone, phosphate and calcium levels between 2015 and 2018 by electrochemiluminescence and spectrophotometry. Cholecalciferol was considered insufficient under 50 nmol/L and severely deficient below 25 nmol/L. Seventy-three percent of children showed hypovitaminosis D and 28% had a severe deficiency. Highest prevalence of deficiency was found in children from Eastern Mediterranean (80%) and African regions (75%). Severe deficiency was more prevalent in the South East Asian (39%) and Eastern Mediterranean regions (33%) and more frequent in females. Deficiency was more frequent and more severe in winter. Hypovitaminosis D increased with age. Two children presented with all three biological manifestations associated to severe hypovitaminosis D (hyperparathyroidism, hypocalcaemia and hypophosphatemia).Conclusion: A majority of migrant children presented with hypovitaminosis D. They should be supplemented to prevent complications. A strategy could be to supplement all children at arrival and during wintertime without regular vitamin D level checks. What is Known: Hypovitaminosis D is frequent in children and can lead to bone-related complications. Migrant children are particularly at risk of deficiency. What is New: Three-quarters of migrant children evaluated at our migrant clinic in Geneva's children hospital are deficient in vitamin D, one third severely. A strategy to correct the deficiency would be to supplement all migrant children at arrival and in winter.

Case Report: Children with Severe Nutritional Rickets in the Naga Region in Northwest Myanmar, on the border with India.

Rickets is an often-neglected, painful, and disabling childhood condition of impaired bone mineralization. In this case series we describe a cluster of 29 children with severe, painful bone deformities who live in the very remote region of Nagaland in northwest Myanmar. Children were found to have low 25-hydroxyvitamin D, elevated parathyroid hormone, and elevated alkaline phosphatase levels, consistent with nutritional rickets secondary to vitamin D deficiency, calcium deficiency, or a combination of the two. After treatment with vitamin D3 and calcium carbonate, significant improvement was seen in symptoms, biochemistry, and radiography. This is the first report of nutritional rickets in Myanmar in more than 120 years. Vitamin D and calcium supplementation, and food fortification for pregnant women and young children may be required to prevent this potentially devastating disease.

Vitamin D, rickets and child abuse: controversies and evidence.

Suboptimal vitamin D status is a global health issue that affects children and adults worldwide. The prevalence of vitamin D deficiency and insufficiency has been well documented in the pediatric population in the United States. Although vitamin D deficiency is common, radiographic findings are uncommon and can be subtle. Additionally, because of the high prevalence of pediatric vitamin D insufficiency, it is commonly identified in young children with fractures. However, the majority of pediatric fractures are caused by trauma to healthy bones. Some, especially in infants and toddlers, are caused by non-accidental trauma. A small percentage is related to medical disease, including those associated with disorders of collagen, disorders of mineralization, and non-fracture mimics. Despite the scientific evidence, among disorders of mineralization, non-rachitic disorders of vitamin D have become a popular non-scientific theory to explain the fractures identified in abused children. Although infants and young children with rickets can fracture bones, the vast majority of fractures identified in abused infants are not caused by bone disease. Here we present a review of the literature on bone disease in the setting of accidental and non-accidental trauma. This context can help physicians remain vigilant about identifying vulnerable young children whose injuries are caused by non-accidental trauma.

Vitamin D and Cardiovascular Disease: An Updated Narrative Review.

During the last two decades, the potential impact of vitamin D on the risk of cardiovascular disease (CVD) has been rigorously studied. Data regarding the effect of vitamin D on CVD risk are puzzling: observational data indicate an inverse nonlinear association between vitamin D status and CVD events, with the highest CVD risk at severe vitamin D deficiency; however, preclinical data and randomized controlled trials (RCTs) show several beneficial effects of vitamin D on the surrogate parameters of vascular and cardiac function. By contrast, Mendelian randomization studies and large RCTs in the general population and in patients with chronic kidney disease, a high-risk group for CVD events, largely report no significant beneficial effect of vitamin D treatment on CVD events. In patients with rickets and osteomalacia, cardiovascular complications are infrequently reported, except for an increased risk of heart failure. In conclusion, there is no strong evidence for beneficial vitamin D effects on CVD risk, either in the general population or in high-risk groups. Whether some subgroups such as individuals with severe vitamin D deficiency or a combination of low vitamin D status with specific gene variants and/or certain nutrition/lifestyle factors would benefit from vitamin D (metabolite) administration, remains to be studied.

Vitamin D for Growth and Rickets in Stunted Children: A Randomized Trial.

BACKGROUND AND OBJECTIVES: Vitamin D is essential for healthy development of bones, but little is known about the effects of supplementation in young stunted children. Our objective was to assess the effect of vitamin D supplementation on risk of rickets and linear growth among Afghan children. METHODS: In this double-blind, placebo-controlled trial, 3046 children ages 1 to 11 months from inner-city Kabul were randomly assigned to receive oral vitamin D3 (100 000 IU) or placebo every 3 months for 18 months. Rickets Severity Score was calculated by using wrist and knee radiographs for 631 randomly selected infants at 18 months, and rickets was defined as a score >1.5. Weight and length were measured at baseline and 18 months by using standard techniques, and z scores were calculated. RESULTS: Mean (95% confidence interval [CI]) serum 25-hydroxyvitamin D (seasonally corrected) and dietary calcium intake were insufficient at 37 (35-39) nmol/L and 372 (327-418) mg/day, respectively. Prevalence of rickets was 5.5% (placebo) and 5.3% (vitamin D): odds ratio 0.96 (95% CI: 0.48 to 1.92); P = .9. The mean difference in height-for-age z score was 0.05 (95% CI: -0.05 to 0.15), P = .3, although the effect of vitamin D was greater for those consuming >300 mg/day of dietary calcium (0.14 [95% CI: 0 to 0.29]; P = .05). There were no between-group differences in weight-for-age or weight-for-height z scores. CONCLUSIONS: Except in those with higher calcium intake, vitamin D supplementation had no effect on rickets or growth.

A joint medico-historical and paleopathological perspective on vitamin D deficiency prevalence in post-Medieval Netherlands.

OBJECTIVE: By applying a joint medico-historical and paleopathological perspective, this paper aims to improve our understanding of factors influencing past vitamin D deficiency in ten Dutch 17th to 19th-century communities of varying socioeconomic status and settlement type. MATERIALS: Vitamin D deficiency is evaluated in 733 individuals of both sexes and all age groups: Silvolde (n = 16), Rotterdam (n = 23), Rhenen (n = 24), Noordwijkerhout (n = 27), Gouda1and 2 (n = 40; n = 59), Roosendaal (n = 51), Den Haag (n = 93), Hattem (n = 113), and Beemster (n = 287). METHODS: Rickets and residual rickets are macroscopically assessed using established criteria. Hypotheses formulated based on medico-historical texts are investigated via multivariate statistical analysis of vitamin D deficiency prevalence. RESULTS: Vitamin D deficiency prevalence ranges from 13.7 % (7/51) in Roosendaal to 48.1 % (13/27) in Noordwijkerhout, with an onset of < 4 years, and higher rates in cities, conforming to medico-historical texts. Patterns of child labor are likely key. In contrast, socioeconomic status did not statistically significantly influence vitamin D deficiency prevalence rates. CONCLUSION: Systematically collected paleopathological data enabled evaluation of medico-historical texts and provided insights into the role that socioeconomic status and settlement type played on the prevalence of vitamin D deficiency. SIGNIFICANCE: Combining medico-historical texts and large-scale paleopathological data enables disease patterning to be embedded in a comprehensive biocultural perspective. LIMITATIONS: Comparisons may be limited by the small sample size of high socioeconomic status nonadults and some of the collections. SUGGESTIONS FOR FUTURE RESEARCH: Analysis of more individuals and sites would improve our understanding of disease patterns.

Demographic Characteristics, Risk Factors, and Presenting Features of Children with Symptomatic Nutritional Rickets: A French Series.

AIM: To describe the demographic characteristics, risk factors, and presenting features of children with symptomatic nutritional rickets in France. METHODS: This is a retrospective study of 38 children diagnosed with nutritional rickets from 1998 to 2019. RESULTS: We observed a higher frequency of rickets in males (74 vs. 26%), in young children (median age at diagnosis: 23 months; 82% were younger than 5 years), and in children with a non-Caucasian ethnic background (89%). Most children were exclusively breastfed (78%) without adequate vitamin D supplementation (89%). The most common presentations were bowed legs (63%), hypocalcemic seizures (21%), and growth retardation (11%). Approximately half (62%) of the children were hypocalcemic. The children presenting with hypocalcemic seizures were significantly younger (0.8 vs. 2.2 years; p = 0.041) and had lower total serum calcium levels (1.44 vs. 2.17 mmol/L; p < 0.0001), higher phosphatemia (1.43 vs. 1.23 mmol/L; p = 0.020), and lower 25-hydroxy vitamin D levels (3 vs. 7 ng/mL; p = 0.020) but similar parathyroid hormone levels (357 vs. 289 ng/mL; p = 0.940) compared to rickets cases who did not experience hypocalcemic seizures. A dilated cardiomyopathy was detected in 14% of the children who had undergone echocardiography. CONCLUSION: Nutritional rickets remains endemic in the pediatric population and its most severe forms can have life-threatening sequelae. Health practitioners need to be cognizant of these facts to raise awareness and screen high-risk populations.

Cost-Effectiveness of Vitamin D Supplementation in Pregnant Woman and Young Children in Preventing Rickets: A Modeling Study.

Background: Literature on the cost of management of rickets and cost-effectiveness of vitamin D supplementation in preventing rickets is lacking. Methods: This study considered the cost-effectiveness of providing free vitamin D supplementation to pregnant women and children <4 years of age with varying degrees of skin pigmentation to prevent rickets in children. Estimates for the prevalence of rickets were calculated using all cases of rickets diagnosed in Central Manchester, UK and census data from the region. Cost of management of rickets were calculated using National Health Service, UK tariffs. The efficacy of vitamin D supplementation was based on a similar programme implemented in Birmingham. Quality of life was assessed using utility estimates derived from a systematic literature review. In this analysis the intervention was considered cost-effective if the incremental cost-effectiveness ratio (ICER) is below the National Institute for Health and Care Excellence, UK cost-effectiveness threshold of £20,000 per Quality-adjusted life year (QALY). Results: Fifty-seven patients (26 dark, 29 medium and 2 light skin tones) were managed for rickets and associated complications over 4-years. Rickets has an estimated annual incidence of 29·75 per 100,000 children <4 years of age. In the dark skin tone population vitamin D supplementation proved to be cost saving. In a medium skin tone population and light skin tone populations the ICER was £19,295 per QALY and £404,047 per QALY, respectively. Conclusion: Our study demonstrates that a vitamin D supplementation to prevent rickets is cost effective in dark and medium skin tone populations.

Vitamina D para la práctica diaria / Vitamin D for daily practice

La vitamina D es una vitamina liposoluble cuya principal función en el organismo es la regulación del metabolismo calcio-fósforo. El receptor de la vitamina D está presente en la mayoría de las células nucleadas de nuestro organismo, por lo que se está descubriendo su intervención en múltiples procesos. Las 3 principales fuentes para su obtención son la radiación ultravioleta, la alimentación y la suplementación. La piel, a través de la radiación solar, proporciona el 90% de la vitamina D que necesitamos. En casos deficitarios se han de repasar los hábitos de exposición solar, alimentación y se ha de valorar la suplementación farmacológica. La medición en el organismo se realiza mediante la determinación de 25-hidroxicolecalciferol y valores por debajo de 20ng/ml se consideran inadecuados. En el momento actual no se recomienda el cribado universal de vitamina D, sino en aquellos casos en los que se sospeche un déficit

Vitamin D is a fat-soluble vitamin which has the regulation of calcium-phosphorus metabolism in the body as its main function. Vitamin D receptor is present in most of the nucleated cells of the body, and its role in multiple body processes is being discovered. The 3 main sources of vitamin D are ultraviolet sun radiation, diet, and supplementation. The skin, through solar radiation, provides 90% of the bodýs vitamin D needs. In cases of low vitamin D, sun exposure habits and diet must be reviewed, and pharmacological supplementation must be assessed. Measurement in the body is performed by determining 25-hydroxycholecalciferol with values below 20ng/ml being considered insufficient. Universal screening of vitamin D is not currently recommended, only in situations where a deficiency is suspected

Vitamin D Toxicity / Toxicidade da Vitamina D

Abstract Fortification of food products with vitamin D was central to the eradication of rickets in the early parts of the 20th century in the United States. In the subsequent almost 100 years since, accumulating evidence has linked vitamin D deficiency to a variety of outcomes, and this has paralleled greater public interest and awareness of the health benefits of vitamin D. Supplements containing vitamin D are now widely available in both industrialized and developing countries, and many are in the form of unregulated formulations sold to the public with little guidance for safe administration. Together, this has contributed to a transition whereby a dramatic global increase in cases of vitamin D toxicity has been reported. Clinicians are now faced with the challenge of managing this condition that can present on a spectrum from asymptomatic to acute life-threatening complications. This article considers contemporary data on vitamin D toxicity, and diagnostic and management strategies relevant to clinical practice.

Resumo A suplementação de produtos alimentares com vitamina D foi fundamental para a erradicação do raquitismo no início do século XX nos Estados Unidos. Nos quase 100 anos subsequentes, o acúmulo de evidências vinculou a deficiência de vitamina D a uma variedade de desfechos, e isso tem levantado grande interesse público e conscientização dos benefícios à saúde da vitamina D. Os suplementos que contêm vitamina D estão agora amplamente disponíveis tanto nos países desenvolvidos quanto naqueles em desenvolvimento, e muitos estão na forma de formulações não regulamentadas, vendidas ao público com poucas orientações para uma administração segura. Juntos, isso contribuiu para uma transição na qual um aumento global dramático nos casos de toxicidade da vitamina D tem sido relatado. Médicos agora enfrentam o desafio de tratar essa condição que pode apresentar um espectro de complicações assintomáticas a agudas, com risco de vida. Este artigo considera dados atualizados sobre a toxicidade da vitamina D e estratégias de diagnóstico e manejo relevantes para a prática clínica.