25-Hydroxyvitamin D in the range of 20 to 100 ng/mL and incidence of kidney stones

Association between serum 25-hydroxyvitamin D concentrations and kidney stone: a cohort study in the UK Biobank

OBJECTIVE

To investigate the association between serum 25(OH)D and kidney stone disease (KSD) in participants from the UK Biobank.

METHODS

We used data from the UK Biobank. Our analysis involved Cox proportional hazards models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) to estimate the association between serum 25(OH)D levels (measured at the time of recruitment) and the risk of KSD, which was determined using hospital records.

RESULTS

This study involved 444,343 participants, with 4,458 cases of KSD identified during an average follow-up period of 12.6 years. Higher 25(OH)D levels were not associated with developing kidney stones in general population model 3 (HR = 0.88 [95% CI 0.77-1.01]). Interestingly, higher serum 25(OH)D concentrations in women over 60 years old were associated with a lower risk of kidney stone disease. The multivariate HRs and 95% CIs for participants who had serum 25(OH)D ≥ 50 nmol/L or ≥ 75 nmol/L, compared with those who were severely deficient (25[OH]D < 25 nmol/L), were 0.74 (0.58-0.95), 0.60 (0.43-0.85) for KSD, respectively (P for trend < 0.01). However, this trend was not statistically significant in the subgroup analysis of serum calcium ion concentration.

CONCLUSION

High 25(OH)D levels were not associated with a higher incidence of kidney stones if serum calcium levels are within a normal range. The findings alleviate physiological concerns regarding the supplementation of vitamin D alone to raise serum 25(OH)D concentration.

Associations between lumbar bone mineral density, serum 25-hydroxyvitamin D and history of kidney stones in adults aged 30-69 years in the USA (NHANES 2011-2018)

OBJECTIVES

Most kidney stones contain calcium, which is closely associated with human bone health. Therefore, we aimed to determine the relationship between the history of kidney stones and human bone health. This study examined the associations between lumbar bone mineral density (BMD), serum 25-hydroxyvitamin D (25-OHD) and a history of kidney stones in individuals aged between 30 years and 69 years.

DESIGN AND DATA ANALYSIS

A multivariate logistic regression model was used to estimate the relationship between lumbar BMD, serum 25-OHD levels and kidney stones in this cross-sectional study. All models incorporated survey sample weights and were adjusted for covariates.

SETTING

National Health and Nutrition Examination Survey (NHANES) 2011-2018. The exposure and outcomes of this study included the lumbar BMD and presence of kidney stones.

PARTICIPANTS

All the 7500 participants for this cross-sectional survey were selected from the NHANES between 2011 and 2018.

MAIN OUTCOME MEASURES

The main outcome of this study was the presence of kidney stones. The interviewers asked the questions on kidney stones while the respondents were at home, using a computer-assisted personal interview system.

RESULTS

Lumbar BMD was negatively correlated with a history of kidney stones in all three multivariate linear regression models; the negative association existed in all genders after adjusting for all confounding factors. In the multiple regression analysis, there was an interaction between serum 25-OHD and lumbar BMD (p<0.05) regarding the influence on kidney stones; the negative association between lumbar BMD and kidney stones was more obvious in the higher 25-OHD group (≥50 nmol/L).

CONCLUSION

The study results suggest that maintaining a high lumbar BMD may reduce the incidence of kidney stone formation. Simultaneously, maintaining a high serum 25-OHD level may be more beneficial in preventing the occurrence or recurrence of stones while ensuring a high lumbar BMD.

Oral and Topical Vitamin D, Sunshine, and UVB Phototherapy Safely Control Psoriasis in Patients with Normal Pretreatment Serum 25-Hydroxyvitamin D Concentrations: A Literature Review and Discussion of Health Implications

Vitamin D, sunshine and UVB phototherapy were first reported in the early 1900s to control psoriasis, cure rickets and cure tuberculosis (TB). Vitamin D also controlled asthma and rheumatoid arthritis with intakes ranging from 60,000 to 600,000 International Units (IU)/day. In the 1980s, interest in treating psoriasis with vitamin D rekindled. Since 1985 four different oral forms of vitamin D (D2, D3, 1-hydroxyvitaminD3 (1(OH)D3) and 1,25-dihydroxyvitaminD3 (calcitriol)) and several topical formulations have been reported safe and effective treatments for psoriasis-as has UVB phototherapy and sunshine. In this review we show that many pre-treatment serum 25(OH)D concentrations fall within the current range of normal, while many post-treatment concentrations fall outside the upper limit of this normal (100 ng/mL). Yet, psoriasis patients showed significant clinical improvement without complications using these treatments. Current estimates of vitamin D sufficiency appear to underestimate serum 25(OH)D concentrations required for optimal health in psoriasis patients, while concentrations associated with adverse events appear to be much higher than current estimates of safe serum 25(OH)D concentrations. Based on these observations, the therapeutic index for vitamin D needs to be reexamined in the treatment of psoriasis and other diseases strongly linked to vitamin D deficiency, including COVID-19 infections, which may also improve safely with sufficient vitamin D intake or UVB exposure.

Metabolic effects of cholecalciferol supplementation in patients with calcium nephrolithiasis and vitamin D deficiency

INTRODUCTION

In this paper, we investigated whether cholecalciferol supplementation may increase the risk of stone recurrence in patients with calcium nephrolithiasis and Vitamin D deficiency.

METHODS

Thirty-three stone formers (56 ± 17 years old, 12 males) with 25(OH)D < 20 ng/mL were considered. Calcium excretion and urine supersaturation with calcium oxalate (ßCaOx) and brushite (ßbsh) were evaluated, both before and after cholecalciferol supplementation. Values of ß > 1 mean supersaturation. Cholecalciferol was prescribed as oral bolus of 100,000-200,000 IU, followed by weekly (5000-10,000 IU) or monthly (25,000-50,000 IU) doses. Calcium intake varied between 800 and 1000 mg/day. In urine, total nitrogen (TNE) was taken as an index of protein intake, sodium as a marker of dietary intake, and net acid excretion (NAE) as an index of acid-base balance.

RESULTS

TNE, sodium, and NAE did not change during the study (p = ns). Compared to baseline values, after cholecalciferol, both serum calcium and phosphate did not vary (p = ns); 25(OH)D increased from 11.8 ± 5.5 to 40.2 ± 12.2 ng/mL (p < 0.01); 1.25(OH)₂D increased from 41.6 ± 17.6 to 54 ± 16 pg/mL (p < 0.01); PTH decreased from 75 ± 27.2 to 56.7 ± 21.1 pg/mL (p < 0.01); urinary calcium increased from 2.7 ± 1.5 to 3.6 ± 1.6 mg/Kg b.w. (p < 0.01); ßbsh increased from 0.9 ± 0.7 to 1.3 ± 1.3 (p = 0.02); whereas ßCaOx varied but not significantly. Before cholecalciferol supplementation, 6/33 patients were hypercalciuric (i.e., urine Ca ≥ 4 mg/Kg b.w.) and increased to 13/33 after cholecalciferol supplementation (pX² = 0.03).

CONCLUSIONS

Cholecalciferol supplementation may increase calcium excretion, or reveal an underlying condition of absorptive hypercalciuria. This may increase both urine supersaturation with calcium salts and stone-forming risk.

Vitamin D and Kidney Stones

This review explores the relationship between vitamin D supplementation and lithogenesis. A causal relationship has been assumed despite myriad studies demonstrating that therapeutic doses of vitamin D do not increase lithogenic risk. Select stone formers may be at increased risk for recurrence with vitamin D supplementation, possibly from CYP24A1 gene mutations. Additionally, the evidence for who is vitamin D deficient, and the benefits of supplementation in those not at risk for rickets, is sparse. Concerns may be avoidable as vitamin D screening appears unnecessary in most patients, and superior pharmacology is available which increases bone density, while decreasing stone formation.

Daily oral dosing of vitamin D3 using 5000 TO 50,000 international units a day in long-term hospitalized patients: Insights from a seven year experience

Vitamin D3 is a secosteroid hormone produced in the skin in amounts estimated up to 25,000 international units (IUs) a day by the action of UVB radiation on 7-dehydrocholesterol. Vitamin D deficiency is common due to both lack of adequate sun exposure to the skin, and because vitamin D is present in very few food sources. Deficiency is strongly linked to increased risk for a multitude of diseases, several of which have historically been shown to improve dramatically with either adequate UVB exposure to the skin, or to oral or topical supplementation with vitamin D. These diseases include asthma, psoriasis, rheumatoid arthritis, rickets and tuberculosis. All patients in our hospital have been routinely screened on admission for vitamin D deficiency since July 2011, and offered supplementation to either correct or prevent deficiency. During this time, we have admitted over 4700 patients, the vast majority of whom agreed to supplementation with either 5000 or 10,000 IUs/day. Due to disease concerns, a few agreed to larger amounts, ranging from 20,000 to 50,000 IUs/day. There have been no cases of vitamin D3 induced hypercalcemia or any adverse events attributable to vitamin D3 supplementation in any patient. Three patients with psoriasis showed marked clinical improvement in their skin using 20,000 to 50,000 IUs/day. Analysis of 777 recently tested patients (new and long-term) not on D3 revealed 28.7% with 25-hydroxyvitaminD3 (25OHD3) blood levels < 20 ng/ml, 64.1% < 30 ng/ml, a mean 25OHD3 level of 27.1 ng/ml, with a range from 4.9 to 74.8 ng/ml. Analysis of 418 inpatients on D3 long enough to develop 25OHD3 blood levels > 74.4 ng/ml showed a mean 25OHD3 level of 118.9 ng/ml, with a range from 74.4 to 384.8 ng/ml. The average serum calcium level in these 2 groups was 9.5 (no D3) vs 9.6 (D3), with ranges of 8.4 to 10.7 (no D3) vs 8.6 to 10.7 mg/dl (D3), after excluding patients with other causes of hypercalcemia. The average intact parathyroid hormone levels were 24.2 pg/ml (D3) vs. 30.2 pg/ml (no D3). In summary, long-term supplementation with vitamin D3 in doses ranging from 5000 to 50,000 IUs/day appears to be safe.

The association between dietary intakes and stone formation in patients with urinary stones in Shiraz

Background: Kidney stone is a common and costly disease, but it may be improved by a healthy diet. The aim of this study was to evaluate the association between dietary intake and stone formation in patients with urinary stones in Shiraz. Methods: In this cross sectional study, 110 patients with kidney stone were selected from Faghihi hospital, Shiraz. Demographic information was collected, and anthropometric indices, disease-related variables, physical activity (using IPAQ), and dietary intake (using food frequency questionnaire, analyzed by Nut 4 software, to estimate micro and macro nutrients) were evaluated. Independent sample t test and one-way ANOVA were used to compare the quantitative variables between the 2 groups and multi groups, respectively. Chi square test was also used to compare qualitative variables. The correlation between variables was determined using Pearson test. Results: Out of 110 participants in this study, 37 (33.6%) were female, with the mean BMI of 27.0 ± 4.68 kg/m2, and 73 (66.4%) were male, with the mean BMI of 24.21±2.96 kg/m2. The mean intake of calcium-containing foods (p=0.02) and high-fructose beverages (p=0.03) was significantly greater in patients with calcium stones compared to those with uric acid stones. The mean intake of high-purine foods was significantly higher in patients with uric acid stones than in those with calcium stones (p=0.007). The mean intake of vitamin A (p=0.02), beta-carotene (p=0.03), and fructose (p=0.03) was significantly higher in patients with calcium stones than in those with uric acid stones, while caffeine intake was significantly higher in patients with uric acid than in those with calcium stones (p=0.01). There was a significant correlation between consumption of high-oxalic beverages (p=0.005, correlation coefficient = 0.26) and high-fructose (p=0.048, correlation coefficient = 0.18) with spontaneous stone expulsion. Conclusion: There was a significant relationship between consuming vitamin A, beta-carotene, and foods containing calcium, purine, fructose, and oxalate and formation of kidney stones. Therefore, adopting a healthy diet and increasing physical activity may be effective in the treatment of kidney stones.

Effects of Vitamin D on Skeletal Muscle and Athletic Performance

Vitamin D is known to be important for calcium homeostasis and bone metabolism. It also has important direct effects on skeletal muscle. Unlike authentic vitamins, which cannot be synthesized in the body, vitamin D is produced in the skin using sunlight. Through its nuclear receptor (ie, vitamin D receptor) located throughout the body, including skeletal muscle, vitamin D initiates genomic and nongenomic pathways regulating multiple actions, including myocyte proliferation and growth. In some studies, vitamin D supplementation has been shown to increase muscle strength, particularly in people who are vitamin D deficient. Higher serum levels of vitamin D are associated with reduced injury rates and improved sports performance. In a subset of the population, vitamin D appears to play a role in muscle strength, injury prevention, and sports performance.

Sunlight exposure: Do health benefits outweigh harm?

Vitamin D is a fat-soluble vitamin whose levels within the body are elevated following sunlight exposure. Numerous studies have shown that sunlight exposure can provide protection to a wide variety of diseases, ranging from different types of tumors to hypertension to type 1 diabetes to multiple sclerosis. Moreover, studies have shown that avoiding sunlight may influence the initiation and progression of some of these diseases. Avoidance of sunlight, coupled with the inclination towards consuming supplements, is becoming the primary choice to obtain vitamin D. The purpose of this article is to present evidences from published literature, to show that the expected benefits of vitamin D supplements are minimized by the potential risk of cardiovascular events and beyond. Since hypovitaminosis D status usually reflects reduced sunlight exposure, the obvious primary replacement should be safe sunlight exposure, and not exogenous supplements.

Association between Circulating Vitamin D Level and Urolithiasis: A Systematic Review and Meta-Analysis

Many studies compared the serum/plasma 1,25 dihydroxyvitamin D₃ (1,25(OH)₂D) and 25 hydroxyvitamin D₃ (25(OH)D) between people with and without nephrolithiasis, and their results were conflicting. After systematically searching PubMed, Web of Science, The Cochrane Library, CNKI, and the Wanfang Database, we conducted a meta-analysis. Thirty-two observational studies involving 23,228 participants were included. Meta-analysis of these studies showed that of stone formers (SFs), calcium SFs had significantly higher concentrations of 1,25(OH)₂D (weighted mean difference (WMD), 10.19 pg/mL; 95% confidence interval (CI), 4.31-16.07; p = 0.0007 and WMD, 11.28 pg/mL; 95% CI, 4.07-18.50; p = 0.002, respectively) than non-stone formers, while the levels of 25(OH)D (WMD, 0.88 ng/mL; 95% CI, -1.04-2.80; p = 0.37 and WMD, -0.63 ng/mL; 95% CI, -2.72-1.47; p = 0.56, respectively) are similar. Compared with controls and normocalciuria SFs, hypercalciuria SFs had increased circulating 1,25(OH)₂D (WMD, 9.41 pg/mL; 95% CI, 0.15-18.67; p = 0.05 and WMD, 2.75 pg/mL; 95% CI, -0.20-5.69; p = 0.07, respectively) and markedly higher 25(OH)D (WMD, 5.02 ng/mL; 95% CI, 0.99-9.06; p = 0.01 and WMD, 5.02 ng/mL; 95% CI, 2.14-7.90; p = 0.0006, respectively). Normocalciuria SFs had elevated 1,25(OH)₂D level (WMD, 6.85 pg/mL; 95% CI, -5.00-18.71; p = 0.26) and comparable 25(OH)D (WMD, 0.94 ng/mL; 95% CI, -3.55-5.43; p = 0.68). Sensitivity analysis generated similar results. Current evidence suggests that increased circulating 1,25(OH)₂D is associated with urinary stones and a higher level of circulating 25(OH)D is significantly associated with hypercalciuria urolithiasis. Further studies are still needed to reconfirm and clarify the role of vitamin D in the pathogenesis of stones.

Vitamin D Intake and the Risk of Incident Kidney Stones

PURPOSE

Kidney stones are a common and painful condition. Longitudinal prospective studies on the association between the intake of vitamin D and the risk of incident kidney stones are lacking.

MATERIALS AND METHODS

We performed a prospective analysis of 193,551 participants in the Health Professionals Follow-up Study and Nurses' Health Study I and II. Participants were divided into categories of total (less than 100, 100 to 199, 200 to 399, 400 to 599, 600 to 999, 1,000 IU per day or greater) and supplemental (none, less than 400, 400 to 599, 600 to 999, 1,000 IU per day or greater) vitamin D intake. During a followup of 3,316,846 person-years there were 6,576 incident kidney stone events. Cox proportional hazards regression models were adjusted for age, body mass index, comorbidities, use of medications and intake of other nutrients.

RESULTS

After multivariate adjustment there was no statistically significant association between vitamin D intake and risk of stones in the HPFS (HR for 1,000 or greater vs less than 100 IU per day 1.08, 95% CI 0.80, 1.47, p for trend = 0.92) and the NHS I (HR 0.99, 95% CI 0.73, 1.35, p for trend = 0.70), whereas there was a suggestion of a higher risk in the NHS II (HR 1.18, 95% CI 0.94, 1.48, p for trend = 0.02). Similar results were found for supplemental vitamin D intake.

CONCLUSIONS

Vitamin D intake in typical amounts was not statistically associated with risk of kidney stone formation, although higher risk with higher doses than those studied here cannot be excluded.

Safety of 50,000-100,000 Units of Vitamin D3/Week in Vitamin D-Deficient, Hypercholesterolemic Patients with Reversible Statin Intolerance

Background:

Vitamin D deficiency (<32 ng/mL) is a reversible cause of statin-intolerance, usually requiring vitamin D3 (50,000-100,000 IU/week) to normalize serum D, allowing reinstitution of statins. Longitudinal safety assessment of serum vitamin D, calcium, and estimated glomerular filtration rate (eGFR) is important.

Aims:

Prospectively assess the safety-efficacy of vitamin D3 therapy.

Materials and Methods:

In 282 statin-intolerant hypercholesterolemic patients for 6 months and in 112 of the 282 patients for 12 months, with low-entry serum vitamin D (<32 ng/mL), we assessed safety-efficacy of vitamin D3 therapy (50,000-100,000 IU/week).

Results:

On mean (66,600 IU) and median (50,000 IU) of vitamin D3/week in 282 patients at 6 months, serum vitamin D rose from pretreatment (21—median) to 46 ng/mL (P < 0.0001), and became high (>100 ng/mL) but not toxic (>150 ng/mL) in 4 patients (1.4%). Median serum calcium was unchanged from entry (9.60 mg/dL) to 9.60 at 6 months (P = .36), with no trend of change (P = .16). Median eGFR was unchanged from entry (84 mL/min/1.73) to 83 at 6 months (P = .57), with no trend of change (P = .59). On vitamin D3 71,700 (mean) and 50,000 IU/week (median) at 12 months in 112 patients, serum vitamin D rose from pretreatment (21—median) to 51 ng/mL (P < 0.0001), and became high (>100 but <150 ng/mL) in 1 (0.9%) at 12 months. Median serum calcium was unchanged from entry (9.60 mg/dL) to 9.60 mg/dL and 9.60 mg/dL at 6 months and 12 months, respectively; P > 0.3. eGFR did not change from 79 mL/min/1.73 at entry to 74 mL/min/1.73 and 77 mL/min/1.73 at 6 months and 12 months, P > 0.3. There was no trend in the change in serum calcium (P > 0.5 for 6 months and 12 months), and no change of eGFR for 6 months and 12 months, P > 0.15.

Conclusions:

Vitamin D3 therapy (50,000-100,000 IU/week) was safe and effective when given for 12 months to reverse statin intolerance in patients with vitamin D deficiency. Serum vitamin D rarely exceeded 100 ng/mL, never reached toxic levels, and there were no significant change in serum calcium or eGFR.

Analysis of vitamin D deficiency in calcium stone-forming patients

PURPOSE

The aim of this study is to analyse the percentage of hypovitaminosis D, as well as its relationship with the various parameters of calcium-phosphate metabolism.

METHODS

A case control study was conducted on 366 patients, divided into two groups: Group 1: 127 non-stone-forming patients, and Group 2: 239 calcium stone forming. A study was performed on calcium-phosphate metabolism and urinary lithogenic factors. The percentage of vitamin D deficiency (25-OH-vitamin D levels <20 ng/ml) between the groups was analysed and compared. The SPSS 20.0 statistics program was used for the analysis, with a p ≤ .05 being considered significant.

RESULTS

The mean age of Group 1 was 52.1 years compared to 49.6 years in Group 2, with no significant differences (p = .07). Vitamin D levels were lower in Group 2 compared to Group 1 (25.7 vs. 28.4 ng/ml, p = .02). A vitamin D deficiency was observed in 28 % of the Group 2 stone-forming patients versus 15.7 % in Group 1 (p = .009), with an odds ratio (OR) of 2.09 (95 % CI; 1.19-3.63). In the stone-forming patients with a vitamin D deficiency, the only difference observed was the higher levels of iPTH compared to those stone-formers with a normal vitamin D (56.9 vs. 45.5 pg/ml, respectively; p = .0001).

CONCLUSION

Calcium stone-forming patients have lower mean levels of vitamin D and a higher percentage of hypovitaminosis D than in non-stone-forming patients. This was only related to increased iPTH levels, with urine calcium and other lithogenic parameters having no obvious effect.

Maternal Versus Infant Vitamin D Supplementation During Lactation: A Randomized Controlled Trial

OBJECTIVE

Compare effectiveness of maternal vitamin D3 supplementation with 6400 IU per day alone to maternal and infant supplementation with 400 IU per day.

METHODS

Exclusively lactating women living in Charleston, SC, or Rochester, NY, at 4 to 6 weeks postpartum were randomized to either 400, 2400, or 6400 IU vitamin D3/day for 6 months. Breastfeeding infants in 400 IU group received oral 400 IU vitamin D3/day; infants in 2400 and 6400 IU groups received 0 IU/day (placebo). Vitamin D deficiency was defined as 25-hydroxy-vitamin D (25(OH)D) <50 nmol/L. 2400 IU group ended in 2009 as greater infant deficiency occurred. Maternal serum vitamin D, 25(OH)D, calcium, and phosphorus concentrations and urinary calcium/creatinine ratios were measured at baseline then monthly, and infant blood parameters were measured at baseline and months 4 and 7.

RESULTS

Of the 334 mother-infant pairs in 400 IU and 6400 IU groups at enrollment, 216 (64.7%) were still breastfeeding at visit 1; 148 (44.3%) continued full breastfeeding to 4 months and 95 (28.4%) to 7 months. Vitamin D deficiency in breastfeeding infants was greatly affected by race. Compared with 400 IU vitamin D3 per day, 6400 IU/day safely and significantly increased maternal vitamin D and 25(OH)D from baseline (P < .0001). Compared with breastfeeding infant 25(OH)D in the 400 IU group receiving supplement, infants in the 6400 IU group whose mothers only received supplement did not differ.

CONCLUSIONS

Maternal vitamin D supplementation with 6400 IU/day safely supplies breast milk with adequate vitamin D to satisfy her nursing infant's requirement and offers an alternate strategy to direct infant supplementation.