Use of vitamin D drops leading to kidney failure in a 54-year-old man

Biotics (Pre-, Pro-, Post-) and Uremic Toxicity: Implications, Mechanisms, and Possible Therapies

In recent years, more scientific data have pointed out the close connection between intestinal microbial community, nutritional habits, lifestyle, and the appearance of various affections located at certain anatomical systems. Gut dysbiosis enhances the formation and accumulation of specific metabolites with toxic potential that induce the appearance of kidney-associated illnesses. Intestinal microbes are involved in the degradation of food, drugs, or other ingested products that lead to the formation of various metabolites that end up in renal tissue. Over the last few years, the possibilities of modulating the gut microbiota for the biosynthesis of targeted compounds with bioactive properties for reducing the risk of chronic illness development were investigated. In this regard, the present narrative review provides an overview of the scientific literature across the last decade considering the relationship between bioactive compounds, pre-, pro-, and post-biotics, uremic toxicity, and kidney-associated affections, and the possibility of alleviating the accumulation and the negative effects of uremic toxins into the renal system.

1,25-Dihydroxyvitamin D3: A Positive Factor for the Osteogenic Differentiation of hPDLSCs and for the Tissue Regenerative Activity of Cell Sheets

This study aims to investigate the effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2VitD3) on osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) and the activity of hPDLSC sheets and the differences in the tissue regeneration activity of hPDLSC sheets on tooth root fragment treated by different methods. Healthy caries-free premolars were collected. The hPDLSCs were obtained by enzymatic digestion. Surface markers of stem cells were analyzed by flow cytometry and the multidirectional differentiation ability of hPDLSCs was detected. During the osteogenic differentiation of hPDLSCs, 1,25(OH)2VitD3 was added and the effect of 1,25(OH)2VitD3 on osteogenic differentiation of hPDLSCs was assessed using Western blotting, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), enzyme-linked immunosorbent assay, cell staining, and immunofluorescence. After hPDLSC sheets were prepared, histology and immunofluorescence analysis of the effect of 1,25(OH)2VitD3 on sheet activity were performed. In addition, root fragments were prepared and treated with scaling, 24% EDTA (ethylenediamide tetraacetic acid), and Er,Cr:YSGG lasers, respectively, and the tissue regeneration activity of hPDLSC sheets on different root fragments were observed. 1,25(OH)2VitD3 promoted the high gene and protein expressions of osteogenic markers ALP (alkaline phosphatase), Runx2, and OPN (osteopontin antibody) in hPDLSCs, along with enhanced ALP activity and staining, alizarin red staining, and immunofluorescence staining, indicating that the osteogenic differentiation ability of hPDLSCs was improved. Extracellular matrix secretion was increased in hPDLSC sheets, along with the positive expressions of the protein markers fibronectin and collagen I, suggesting that 1,25(OH)2VitD3 could enhance these effects. In addition, the root fragments treated by Er,Cr:YSGG laser were more suitable for the attachment and regeneration of hPDLSC sheets, demonstrating that 1,25(OH)2VitD3 could improve the tissue regeneration performance of these sheets. 1,25(OH)2VitD3 can promote osteogenic differentiation of hPDLSCs and thus plays an active role in hPDLSC sheet formation and tissue regeneration. In addition, the Er,Cr:YSGG laser can be used as the recommended treatment method for the root surface regenerated by hPDLSCs.

Too much of a good thing: A case series of rare yet pertinent causes of hypercalcaemia and acute kidney injury

Calcium compounds and vitamin D supplements are readily available as over-the-counter preparations. Whilst integral in maintaining calcium homeostasis in certain patients, excess exogenous intake of these preparations can have deleterious effects, particularly in terms of renal function. We look at the cases of two patients, aged 52 and 34, who were referred into hospital with hypercalcaemia and acute kidney injury (AKI). Both individuals reported regular and prolonged self-medication with unregulated over-the-counter supplements containing calcium carbonate and vitamin D, respectively. Prompt investigation and treatment enabled an element of reversibility of the AKI in both the cases, with further improvement in renal function over time. We emphasise the importance of recognising the overuse of exogenous vitamin D supplements and calcium compounds as rare yet treatable causes of AKI associated with hypercalcaemia and discuss how raising public awareness into the risks posed by self-medication of over-the-counter medicines is paramount.

Associations Between 25-Hydroxyvitamin D, Kidney Function, and Insulin Resistance Among Adults in the United States of America

Background

Although many molecular studies have tried to explore the relationship between vitamin D metabolism and kidney function, the association between 25-hydroxyvitamin D [25(OH)D] and kidney function is still controversial. Previous studies reported that low vitamin D status and decreased kidney function were associated with insulin resistance (IR). However, neither of them was confirmed by large population-based studies. This study evaluated the associations between 25(OH)D and kidney function and the associations between both of them and IR among adults in the United States of America (USA).

Methods

We analyzed 36,523 adults from the National Health and Nutrition Examination Survey (NHANES) (2001–2014). Kidney function was assessed by the estimated glomerular filtration rate (eGFR), and IR was assessed by homeostasis model assessment (HOMA-IR). All data were survey-weighted, and corresponding linear regression models were performed to examine the associations.

Results

The mean serum 25(OH)D levels were found to be increased in participants with decreased kidney function (eGFR <90 ml/min/1.73 m2), and each unit of decreased serum 25(OH)D concentrations predicted 0.453 ml/min/1.73 m2 (95% CI: 0.426 to 0.480, p < 0.0001) higher eGFR. In addition, each unit of decreased eGFR was associated with 0.007 higher HOMA-IR, while each unit of decreased 25(OH)D concentrations led to 0.025 higher HOMA-IR.

Conclusions

Serum 25-hydroxyvitamin D concentrations were negatively associated with kidney function. IR appears in the early stage of kidney dysfunction, and both serum 25(OH)D concentrations and kidney function are negatively associated with IR. Clinicians should maintain appropriate serum 25(OH)D concentrations and doses of vitamin D supplements for different populations. The underlying mechanism of these associations still needs more research, especially the negative association between serum 25(OH)D concentrations and kidney function.

Vitamin D Toxicity Managed with Peritoneal Dialysis

Vitamin D deficiency is a global health issue that afflicts more than one billion children and adults worldwide. Vitamin D supplementation has increased over the years, whether through medical prescriptions, over-the-counter, or online purchasing. This is driven by a more recognized association between vitamin D sufficiency status and lower risk of cancer. In addition, more recently, it is used as a potential prophylactic and treatment for COVID-19 infection. This can lead to toxicity from overingestion. While rare, it has been reported in the literature. In this case report, we present a 75-year-old man with severe hypercalcemia secondary to vitamin D toxicity managed with peritoneal dialysis. He presented with biochemical evidence of hypercalcemia, acute kidney injury, and pancreatitis. Workup for his hypercalcemia led to the diagnosis of vitamin D toxicity as shown by a level greater than 200 ng/dL (Ref: 20-50 ng/mL) was confirmed by liquid chromatography-mass spectroscopy. Cornerstone medical management of hypercalcemia was provided which included aggressive intravenous fluid hydration, intravenous diuretics, calcitonin, bisphosphonate, and corticosteroid therapy. At every interruption of therapy, calcium levels trended upward. A thorough literature review yielded the finding of a sole case report from 1966 presented at the Third International Congress of Nephrology, in which peritoneal dialysis was used in the management of vitamin D toxicity and hypercalcemia. This modality is established to cause vitamin D deficiency. In collaboration with the nephrology team, 10 sessions of peritoneal dialysis were undertaken with resolution of hypercalcemia and downtrend in 25-hydroxyvitamin D levels as measured by dilution.

1α,25-dihydroxyvitamin D3 promotes early osteogenic differentiation of PDLSCs and a 12-year follow-up case of early-onset vitamin D deficiency periodontitis

Periodontitis is a chronic periodontal disease that contributes to tooth loss. In recent years, many animal studies have reported that vitamin D (VitD) deficiency results in chronic periodontitis. However, no studies have reported cases of early-onset periodontitis with VitD deficiency. This study reports a 5-year-old male patient with early-onset periodontitis, VitD deficiency and VitD receptor (VDR) mutation. The patient was treated with VitD and calcium, and received systematic periodontal treatment. During the 12-year treatment, the periodontal conditions of this patient were stable. Our in vitro study found that VitD could promote the expression of alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), bone morphogenetic protein 2 (BMP2), bone gamma-carboxyglutamate protein (BGLAP), and VDR in the early osteogenic differentiation of periodontal ligament stem cells (PDLSCs). Meanwhile, VitD could downregulate mRNA expression levels of Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-1β (IL-1β) and protein levels of IL-6 in the tumor necrosis factor-α (TNF-α) -induced inflammation of PDLSCs. Therefore, sufficient VitD supply can be a potential treatment for VitD deficiency induced early-onset periodontitis.

Association of Genetic Variants Related to Serum Calcium Levels with Reduced Bone Mineral Density

CONTEXT

The role of serum calcium in bone metabolism is unknown, even though calcium/vitamin D supplementations have been widely used and are expected to improve bone health. We aim to determine the independent role of serum calcium in bone mineral density (BMD).

DESIGN AND SETTING

Two epidemiological analyses with 5478 and 5556 participants from the National Health and Nutrition Examination Survey (NHANES) 2003 to 2006 and the Hong Kong Osteoporosis Study (HKOS) to evaluate the cross-sectional association of serum calcium with BMD. Two-sample Mendelian randomization (MR) studies using genetic variations as instrumental variables to infer causality. Summary statistics of genome-wide association study of serum calcium (N = 39 400) and lifelong whole-body BMD (N = 66 628) were used.

MAIN OUTCOME MEASURE

BMD measured by dual-energy X-ray absorptiometry.

RESULTS

In NHANES 2003-6 and HKOS, each standard deviation (SD) increase in serum calcium was significantly associated with 0.036-0.092 SD decrease in BMD at various sites (all P < .05). In multivariable inverse-variance weighted MR analysis, genetic predisposition to higher serum calcium level was inversely associated with whole-body BMD after adjustment for serum parathyroid hormone, vitamin D, and phosphate (-0.431 SD per SD increase in serum calcium; 95% CI: -0.773 to -0.089, P = .014). Similar estimates were obtained in sensitivity analyses.

CONCLUSIONS

Our study reveals that genetic predisposition to higher serum calcium level per se may have a negative impact on bone metabolism. Whether increased serum calcium caused by calcium/vitamin D supplementations would have the same negative effect on bone remains unknown, which warrants further investigation. In addition to other adverse clinical outcomes, careful use of high-dose supplementations is required.