scholarly journals Infantile hypercalcaemia type 1: a vitamin D-mediated, under-recognised cause of hypercalcaemia

2021 ◽  
Vol 2021 ◽  
Author(s):  
Ryizan Nizar ◽  
Nathan W P Cantley ◽  
Jonathan C Y Tang
Keyword(s):  
Vitamin D ◽  
Autosomal Recessive Disorder ◽  
Molecular Genetic Analysis ◽  
The Body ◽  
List Type ◽  
Vitamin D Metabolites ◽  
Vitamin D Metabolism ◽  
History Of ◽  
25 Oh Vitamin D

Summary A 33-year-old gentleman of Egyptian heritage presented with a 21 years history of unexplained and recurrent hypercalcaemia, nephrolithiasis, nephrocalcinosis, and myocarditis. A similar history was also found in two first-degree relatives. Further investigation into the vitamin D metabolism pathway identified the biochemical hallmarks of infantile hypercalcaemia type 1 (IIH). A homozygous, likely pathogenic, variant in CYP24A1 was found on molecular genetic analysis confirming the diagnosis. Management now focuses on removing excess vitamin D from the metabolic pathway as well as reducing calcium intake to achieve serum-adjusted calcium to the middle of the reference range. If undiagnosed, IIH can cause serious renal complications and metabolic bone disease. Learning points Infantile hypercalcaemia type 1 (IIH) is an autosomal recessive disorder characterised by homozygous mutations in the CYP24A1 gene that encodes the 24-hydroxylase enzyme used to convert active vitamin D metabolites such as 1,25-(OH)2-vitamin D into their inactive form. IIH should be questioned in individuals presenting with a history of unexplained hypercalcaemia, especially if presenting from childhood and/or where there is an accompanying family history of the same in first and/or second degree relatives, causing complications such as nephrocalcinosis, pericarditis, and calcium-based nephrolithiasis. Associated biochemistry of IIH is persistent mild to moderate hypercalcaemia, normal or raised 25-(OH)-vitamin D and elevated 1,25-(OH)2-vitamin D. An elevated ratio of 25-(OH)-vitamin D to 24,25-(OH)2-vitamin D can be a useful marker of defects in the 24-hydroxylase enzyme, whose measurement can be facilitated through the supra-regional assay service. Management should focus on limiting the amount of vitamin D introduced into the body either via sunlight exposure or supplementation in addition to calcium dietary restriction to try and maintain appropriate calcium homeostasis

scholarly journals Implications of Vitamin D Research in Chickens can Advance Human Nutrition and Perspectives for the Future

2021 ◽  
Author(s):  
Matthew F Warren ◽  
Kimberly A Livingston
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Vitamin D Supplementation ◽  
The Body ◽  
Human Nutrition ◽  
Vitamin D Metabolites ◽  
Vitamin D Metabolism ◽  
Related Research ◽  
Vitamin D Intake ◽  
Increased Risk

Abstract The risk of vitamin D insufficiency in humans is a global problem that requires improving ways to increase vitamin D intake. Supplements are a primary means for increasing vitamin D intake, but without a clear consensus on what constitutes vitamin D sufficiency, there is toxicity risk with taking supplements. Chickens have been used in many vitamin D-related research studies, especially studies involving vitamin D supplementation. Our state-of-the-art review evaluates vitamin D metabolism and how the different hydroxylated forms are synthesized. We provide an overview with how vitamin D is absorbed, transported, excreted, and what tissues in the body store vitamin D metabolites. We also discuss a number of studies involving vitamin D supplementation with broilers and laying hens. Vitamin D deficiency and toxicity are also described and how they can be caused. The vitamin D receptor (VDR) is important for vitamin D metabolism. However, there is much more that can be understood with VDR in chickens. Potential research aims involving vitamin D and chickens should explore VDR mechanisms which could lead to newer insights with VDR. Utilizing chickens in future research to help with elucidating vitamin D mechanisms has great potential to advance human nutrition. Finding ways to increase vitamin D intake will be necessary because the coronavirus 2019 disease (COVID-19) pandemic is leading to increased risk of vitamin D deficiency in many populations. Chickens can provide a dual purpose with addressing pandemic-caused vitamin D deficiency: 1) vitamin D supplementation gives chickens added value with possibly leading to vitamin D-enriched meat and egg products; and 2) chickens’ use in research provides data for translational research. Expanding vitamin D-related research in chickens to include more nutritional aims in vitamin D status has great implications with developing better strategies to improve human health.

scholarly journals Evaluation of Vitamin D Metabolism in Patients with Type 1 Diabetes Mellitus in the Setting of Cholecalciferol Treatment

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3873
Author(s):  
Alexandra Povaliaeva ◽  
Ekaterina Pigarova ◽  
Artem Zhukov ◽  
Viktor Bogdanov ◽  
Larisa Dzeranova ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Vitamin D ◽  
Type 1 Diabetes ◽  
Type 1 Diabetes Mellitus ◽  
Controlled Study ◽  
Affinity Constant ◽  
Vitamin D Metabolites ◽  
Vitamin D Metabolism ◽  
Vitamin D Levels

In this prospective controlled study, we examined 25 adults with adequately controlled (HbA1c level < 8.0%) type 1 diabetes mellitus (T1DM) and 49 conditionally healthy adults, intending to reveal the diversity of vitamin D metabolism in the setting of cholecalciferol intake at a therapeutic dose. All patients received a single dose (150,000 IU) of cholecalciferol aqueous solution orally. Laboratory assessments including serum vitamin D metabolites (25(OH)D3, 25(OH)D2, 1,25(OH)2D3, 3-epi-25(OH)D3 and 24,25(OH)2D3), free 25(OH)D, vitamin D-binding protein (DBP) and parathyroid hormone (PTH) as well as serum and urine biochemical parameters were performed before the intake and on Days 1, 3 and 7 after the administration. The studied groups had no significant differences in baseline parameters except that the patients with diabetes showed higher baseline levels of free 25(OH)D (p < 0.05). They also lacked a correlation between the measured and calculated free 25(OH)D in contrast to the patients from the control group (r = 0.41, p > 0.05 vs. r = 0.88, p < 0.05), possibly due to the glycosylation of binding proteins, which affects the affinity constant for 25(OH)D. The elevation of vitamin D levels after the administration of cholecalciferol was comparable in both groups, with slightly higher 25(OH)D3 levels observed in the diabetes group throughout the study since Day 1 (p < 0.05). Overall, our data indicate that in patients with adequately controlled T1DM 25(OH)D3 levels and the therapeutic response to cholecalciferol is similar to that in healthy individuals.

scholarly journals Fasting and Exercise Induce Changes in Serum Vitamin D Metabolites in Healthy Men

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1963
Author(s):  
Małgorzata Żychowska ◽  
Rafał Rola ◽  
Andżelika Borkowska ◽  
Maja Tomczyk ◽  
Jakub Kortas ◽  
...  
Keyword(s):  
Vitamin D ◽  
Repeated Measures ◽  
Serum Vitamin ◽  
The Body ◽  
Vitamin D Metabolites ◽  
Serum Samples ◽  
Vitamin D Metabolism ◽  
Serum Vitamin D ◽  
Repeated Measures Design ◽  
Before And After

Background: Vitamin D plays pleiotropic roles in the body and hence, changes in its metabolism and distribution during starvation could play an important role in the adaptive response to famine. We aimed to identify the responses of some vitamin D metabolites to 8 d of fasting and exercise. Methods: A repeated-measures design was implemented, in which 14 male volunteers fasted for 8 d and performed an exercise test before and after fasting. Serum samples were collected on day 1 after night fasting and after 8 d of complete food restriction, before and 1 h and 3 h after exercise. Results: After 8 d of fasting, compared with baseline values, serum 24,25(OH)2D3 and 3-epi-25(OH)D3 levels significantly increased; those of 25(OH)D3 and 1,25(OH)2D3 were unaffected; and those of 25(OH)D2 decreased. Exercise on the first day of fasting induced an increase in serum 3-epi-25(OH)D3 levels, while exercise performed after 8 d of fasting induced an increase in 25(OH)D3, 24,25(OH)2D3, 25(OH)D2, and 3-epi-25(OH)D3 levels. Conclusion: Increases in 24,25(OH)2D3 and 3-epi-25(OH)D3 levels imply that fasting stimulates vitamin D metabolism. The effects of exercise on serum vitamin D metabolites, which are most pronounced after fasting and in subjects with serum 25(OH)D3 above 25 ng/mL, support the notion that fasting and exercise augment vitamin D metabolism.

scholarly journals Type II Vitamin D Dependent Rickets: A Case Report

1970 ◽  
Vol 30 (1) ◽  
pp. 46-49
Author(s):  
Kalpana K Malla ◽  
Tejesh Malla ◽  
Chandan Shaw ◽  
Anna Thapalial
Keyword(s):  
Vitamin D ◽  
Case Report ◽  
Autosomal Recessive ◽  
Autosomal Recessive Disorder ◽  
The Body ◽  
Type Ii ◽  
Paediatric Society ◽  
Vitamin D Metabolism ◽  
Key Words Rickets ◽  
Resistant Rickets

Vitamin D-dependent rickets Type II is a rare autosomal recessive disorder. Alopecia of the scalp or the body is seen in some families with Vitamin D-dependent rickets Type II. We report a child with this disease, and review the salient features of this disease with emphasis on the associated alopecia. Due to lack of facilities for estimation of 1, 25(OH)2 D and parathyroid hormone, alopecia remains the only clue to the diagnosis of this rare syndrome in association with resistant rickets. Key words: Rickets, Vitamin D metabolism DOI: 10.3126/jnps.v30i1.2460 Journal of Nepal Paediatric Society Vol.30(1) 2010 46-49

scholarly journals Parathyroid hormone-independent hypercalcemia and hypercalciuria of a patient with nephrolithiasis and nephrocalcinosis and impaired vitamin D metabolism due to a defect in the CYP24A1 gene

2021 ◽  
Vol 24 (1) ◽  
pp. 26-33
Author(s):  
L. Ya. Rozhinskaya ◽  
A. S. Pushkareva ◽  
E. O. Mamedova ◽  
V. P. Bogdanov ◽  
V. V. Zakharova ◽  
...  
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Calcium Absorption ◽  
Genetic Research ◽  
Autosomal Recessive Disorder ◽  
Malignant Neoplasms ◽  
Vitamin D Metabolites ◽  
Active Metabolites ◽  
Vitamin D Metabolism ◽  
Severe Hypercalcemia

Hypercalcemia associated with impaired vitamin D metabolism is a rare autosomal recessive disorder. The mechanism of this pathology is the impairment of inactivation of active metabolites of vitamin D because of mutations in the CYP24A1 gene, which leads to an increase of calcium absorption and the development of hypercalcemia, hypercalciuria, nephrocalcinosis and nephrolithiasis. The phenotype of the disease ranges from severe forms which are diagnosed in early infancy (severe hypercalcemia associated with dehydration, vomiting, nephrocalcinosis, and sometimes death) to milder forms, that often are diagnosed in adulthood and manifested with recurrent nephrolithiasis and nephrocalcinosis. Differential diagnosis is carried out with the most common causes of hypercalcemia: primary hyperparathyroidism and malignant neoplasms. To diagnose, the determination of vitamin D metabolites and genetic research are used. As a treatment for mild forms, it is recommended to limit dairy products, to keep a drinking regimen, to refuse taking vitamin D and calcium preparations, and use of sunscreens. The article presents a clinical case of parathyroid hormone-independent hypercalcemia due to mutation of the CYP24A1 gene of a 20-year-old patient suffering from nephrolithiasis and nephrocalcinosis since the age of 16 with a confirmed violation of vitamin D metabolism.

PROVISION OF VITAMIN D FOR CHILDREN AND ADOLESCENTS IN THE CITY OF ULAN-UDE

2021 ◽  
Vol 100 (3) ◽  
pp. 295-300
Author(s):  
N.B. Gomboeva ◽  
◽  
E.I. Grigoryeva ◽  
Keyword(s):  
Vitamin D ◽  
Children And Adolescents ◽  
Vitamin D Deficiency ◽  
Respiratory Infections ◽  
Sharp Decrease ◽  
The Body ◽  
Severe Deficiency ◽  
Significant Difference ◽  
25 Oh Vitamin D ◽  
The City

The proven relationship between the frequency of influenza and acute respiratory infections in children with vitamin D deficiency and the data on the relationship between a high mortality rate from SARS-CoV-2 in patients with low levels of vitamin D in the body under conditions of a forced sharp decrease in the level of insolation in the period from March 11, 2020 dictated the relevance assessing the vitamin D supply of children and adolescents in educational organizations of the city of Ulan-Ude. Purpose of the study: to assess the vitamin D supply of children and adolescents living in the city of Ulan-Ude. Methods: in a non-randomized, single-center, transverse (one-stage) uncontrolled comparative study, the concentration of 25(OH) vitamin D – 25(OH)D – in the blood serum of children and adolescents in Ulan-Ude was studied from May 22 to May 24, 2020. Moderate vitamin D deficiency (deficiency) was determined when the content of 25(OH)D was in the range of 20–30 ng/ml, the deficiency was within the limits, and the severe deficiency was <10 ng/ml. Results: assessment of vitamin D provision was carried out in 60 children aged 10 to 17 years (15 [11; 16] years), of which 19 boys, 41 girls. Children were divided into 2 groups depending on age: 10–11 years old (grade 5) (n=27) and 15–17 years old (grades 9–11) (n=33). Deficiency of vitamin D was found in 4 (15%), 11 (33%); deficit – in 19 (70%), 18 (55%); severe deficiency – in 2 (7%), 4 (12%), respectively. Along with low indicators of the provision of children and adolescents in the city of Ulan-Ude, an even lower provision of children and adolescents of Buryats was noted. The concentration of vitamin D in Buryat children and adolescents below normal (less than 30 ng/ml) was found in 35 (100%) children and adolescents, deficiency – in 8 (23%) children, vitamin D deficiency – in 21 (60%) children and severe deficiency – in 6 (17%). A statistically significant difference in the content of 25(OH)D between children and adolescents of Russian nationality and Buryats was revealed (p=0,0056). Evaluation of the diet showed that the frequency of consumption of fish as a source of vitamin D by children and adolescents is low. Conclusion: there is a high incidence of vitamin D deficiency and deficiency, which amounted to 97% in the examined children and adolescents living in the city of Ulan-Ude, more pronounced in Buryat children and adolescents, which requires organizational measures to replenish the vitamin D deficiency.

scholarly journals Assessment of Vitamin D Metabolism in Patients with Cushing’s Disease in Response to 150,000 IU Cholecalciferol Treatment

Nutrients ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 4329
Author(s):  
Alexandra Povaliaeva ◽  
Viktor Bogdanov ◽  
Ekaterina Pigarova ◽  
Artem Zhukov ◽  
Larisa Dzeranova ◽  
...  
Keyword(s):  
Vitamin D ◽  
Cushing’S Disease ◽  
Serum Vitamin ◽  
Urinary Free Cortisol ◽  
Cushing's Disease ◽  
Control Group ◽  
Vitamin D Metabolites ◽  
Vitamin D Metabolism ◽  
Serum Vitamin D ◽  
Free Cortisol

In this study we aimed to assess vitamin D metabolism in patients with Cushing’s disease (CD) compared to healthy individuals in the setting of bolus cholecalciferol treatment. The study group included 30 adults with active CD and the control group included 30 apparently healthy adults with similar age, sex and BMI. All participants received a single dose (150,000 IU) of cholecalciferol aqueous solution orally. Laboratory assessments including serum vitamin D metabolites (25(OH)D3, 25(OH)D2, 1,25(OH)2D3, 3-epi-25(OH)D3 and 24,25(OH)2D3), free 25(OH)D, vitamin D-binding protein (DBP) and parathyroid hormone (PTH) as well as serum and urine biochemical parameters were performed before the intake and on Days 1, 3 and 7 after the administration. All data were analyzed with non-parametric statistics. Patients with CD had similar to healthy controls 25(OH)D3 levels (p > 0.05) and higher 25(OH)D3/24,25(OH)2D3 ratios (p < 0.05) throughout the study. They also had lower baseline free 25(OH)D levels (p < 0.05) despite similar DBP levels (p > 0.05) and lower albumin levels (p < 0.05); 24-h urinary free cortisol showed significant correlation with baseline 25(OH)D3/24,25(OH)2D3 ratio (r = 0.36, p < 0.05). The increase in 25(OH)D3 after cholecalciferol intake was similar in obese and non-obese states and lacked correlation with BMI (p > 0.05) among patients with CD, as opposed to the control group. Overall, patients with CD have a consistently lower 25(OH)D3/24,25(OH)2D3 ratio, which is indicative of a decrease in 24-hydroxylase activity. This altered activity of the principal vitamin D catabolism might influence the effectiveness of cholecalciferol treatment. The observed difference in baseline free 25(OH)D levels is not entirely clear and requires further study.

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