Management of hypovitaminosis D in patients with primary hyperparathyroidism

Safety and efficacy of common vitamin D supplementation in primary hyperparathyroidism and coexistent vitamin D deficiency and insufficiency: a systematic review and meta-analysis

PURPOSE

Primary hyperparathyroidism (PHPT) is characterized by excessive secretion of parathyroid hormone (PTH). Vitamin D deficiency can stimulate parathyroid secretion. However, whether to correct vitamin D deficiency in patients with PHPT is controversial. We aimed to evaluate the safety and efficacy of vitamin D replacement in patients with PHPT.

METHODS

We searched PubMed, Cochrane Library, and Embase. The relevant data were extracted from the included documents. The methodological items for non-randomized studies score entries were used for evaluation of quality. Review Manager 5.3 and Stata 12.0 were used for statistical analysis.

RESULTS

A total of 11 articles were included with a total of 388 patients. The serum calcium mean difference (MD) was - 0.06 mg/dL [95% confidence interval (95% CI) - 0.16, 0.04]. Subgroup analysis showed that serum calcium levels did not change if the intervention time exceeded 1 month. The 24-h urinary calcium MD was 36.78 mg/day (95% CI - 37.15, 110.71), which indicated that there was no significant effect of vitamin D supplementation on 24-h urinary calcium levels. The MD of PTH was - 16.01 pg/mL (95% CI - 28.79, - 3.24). Subgroup analysis according to the intervention time showed that vitamin D intervention for more than 1 month significantly reduced PTH levels. The ALP MD was - 10.81 U/L (95% CI - 13.98, - 7.63), which indicated Vitamin D supplementation reduced its level. The MD of 25-hydroxyvitamin D was 22.09 μg/L (95% CI 15.01, 29.17), and no source of heterogeneity was found.

CONCLUSION

Vitamin D supplementation in patients with PHPT and vitamin D deficiency significantly reduces PTH and ALP levels without causing hypercalcemia and hypercalciuria.

Low 25-Hydroxyvitamin D in Primary Hyperparathyroidism: Enhanced Conversion Into 1,25-Hydroxyvitamin D May Not Be "True" Deficiency

Vitamin D deficiency is reported in individuals with primary hyperparathyroidism (PHP). However, decreased 25OHD may be attributed to enhanced conversion into 1,25‐hydroxyvitamin D [1,25(OH)D]. To examine vitamin D metabolism in individuals with PHP, serum calcium, PTH, 25OHD, and 1,25(OH)D levels were determined in 210 adults: 102 with PHP, 40 with normal 25OHD, and 68 with vitamin D deficiency. Concentrations were redetermined in 37 individuals with PHP following vitamin D supplementation and 43 patients postsurgery. Comparisons were conducted by Student's t test and ANOVA. Correlations were assessed between PTH and 25OHD, 1,25(OH)D, and 1,25(OH)D/25OHD in individuals with PHP. Calcium, PTH, and 1,25(OH)D were higher (p < 0.001) in individuals with PHP (11.4 ± 0.4, 116 ± 21, 79 ± 6) than in individuals with normal 25OHD (9.6 ± 0.2, 49 ± 5, 57 ± 6) and vitamin D deficiency (9.3 ± 0.2, 62 ± 6, 32 ± 4). Compared with individuals with normal 25OHD (47 ± 5), 25OHD was lower (18 ± 3), but not different from subjects with vitamin D deficiency (15 ± 2). In individuals with PHP, vitamin D2 supplementation induced rises in 1,25(OH)D and calcium without lowering PTH, whereas postsurgery, calcium, PTH, 25OHD, and 1,25(OH)D normalized. Finally, in individuals with PHP, significant correlations (p < 0.01) were documented between PTH and calcium (r = 0.74), 25OHD (r = −0.43), 1,25(OH)D (r = 0.52), and 1,25(OH)D/25OHD (r = 0.46); and between 1,25(OH)D/25OHD and calcium (r = 0.47). Subnormal 25OHD in most individuals with PHP may be attributed to enhanced conversion to 1,25(OH)D—not “true” vitamin D deficiency—although in some patients, both PHP and vitamin D deficiency coexisted. Moreover, vitamin D supplementation exaggerated hypercalcemia in individuals with PHP. © 2020 The Author. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

The impact of vitamin D status and parameters of calcium metabolism in patients with primary hyperparathyroidism

BACKGROUND

There is ample evidence associating vitamin D deficiency in primary hyperparathyroidism (PHP) patients with more severe disease manifestations and increased risk of postoperative hypocalcemia. Yet, there is limited data regarding the safety of vitamin D repletion in these patients.

AIM

To assess the safety of vitamin D repletion in PHP patients in a real-world setting.

DESIGN

We included patients with asymptomatic PHP and few symptomatic patients who declined surgery, followed in our clinic, and treated on a routine basis with 2000 IU/day of vitamin D3.

METHODS

Serum calcium (sCa), PTH, 25-hydroxyvitamin D, and 24 h urinary calcium (uCa) and creatinine collections were compared between the lowest and the highest vitamin D time points.

RESULTS

There were 40 patients of a mean age was 63 ± 10 years. 25(OH)D at lowest and highest vitamin D time points was 15.5 ± 6.2 ng/ml and 33.2 ± 8, respectively (P < 0.001). Serum calcium was not affected by the changes in vitamin D levels. In none of the patients did sCa exceed 11.5 mg/dL. uCa was 220 ± 110 mg/24 h at the lowest vitamin D time point and 260 ± 140 at the highest vitamin D time point (P = 0.14). uCa exceeded 400 mg/24 h in two vs. five patients (P = 0.23) at the lowest and highest vitamin D time points, respectively. PTH was not significantly different between the different vitamin D time points.

DISCUSSION/CONCLUSION

Vitamin D repletion in PHP seems safe. Considering the documented adverse influence of vitamin D deficiency in PHP, particularly on skeletal manifestations and on the postoperative course, vitamin D repletion is warranted.

Vitamin D Status and Supplementation in the Critically Ill

Vitamin D deficiency has recently been recognized as a widespread global disorder. Generally considered a direct extension of malnutrition, even subclinical hypovitaminosis D is now recognized in adequately nourished populations. Compared to the general population, the prevalence of hypovitaminosis D is greater in the critically ill population. In fact, several studies have shown poorer outcomes in critically ill patients discovered to be vitamin D deficient or insufficient. Controversy persists regarding vitamin D measurements, quantity of supplementation, and appropriate target level in various populations. Vitamin D has a vital role in calcium homeostasis and extra-skeletal health, such as immune function. Therefore, vitamin D supplementation may have a role for improving outcomes in critically ill patients. In this review, we will first discuss the metabolism and function of vitamin D under normal physiologic conditions. We will then explore the prevalence and prognostic value of vitamin D deficiency in critical illness. Finally, we will examine recent trials focusing on appropriate dosing, route of administration, and outcomes associated with vitamin D supplementation in the ICU.

Seasonal changes in serum calcium, PTH and vitamin D levels in patients with primary hyperparathyroidism

BACKGROUND

Seasonal variations of 25-hydroxyvitamin D, PTH and calcium levels are not well characterized in primary hyperparathyroidism (PHPT). Our objectives were to characterize seasonal changes in these parameters in PHPT patients, and to assess whether these seasonal changes affect clinical decision making.

METHODS

This is a retrospective study based on the electronic medical records of Clalit Health service in the south of Israel between 2000 and 2012. Patients 18years and older with PHPT (PTH>upper limit of norm (ULN) and serum calcium>10.5mg%) were included. Patients with renal failure or on Thiazide diuretics were excluded. All serum levels of calcium, PTH and 25-hydroxyvitamin D were collected and then stratified according to season.

RESULTS

792 patients were classified as PHPT (72.2% female) and had a total of 2659 PTH tests, 1395 25-hydroxyvitamin D tests and 7426 calcium test. Fifty six percent of 25-hydroxyvitamin D levels were <50nmol/L. Seasonality was demonstrated in all three parameters: mean 25-hydroxyvitamin D was 13% higher in the summer compared to the winter (P<0.001), median PTH values showed opposite trend with a fall of about 8.4% in summer compared to winter (P<0.001). Calcium levels were higher during the autumn with a rise of about 0.2mg/dL in the mean calcium levels compared to spring and summer (P<0.001). The odds ratio of calcium level above 11.5mg/dL is highest in the autumn (OR=1.275, P=0.018).

CONCLUSION

We show seasonal variation in serum 25-hydroxyvitamin D, PTH, and calcium levels in patients with PHPT. These seasonal variations cause transition to pathological values that may influence diagnosis and treatment of PHPT patients.

Mild primary hyperparathyroidism as defined in the Italian Society of Endocrinology's Consensus Statement: prevalence and clinical features

BACKGROUND

Mild primary hyperparathyroidism (PHPT) was recently clearly defined for the first time. Our study was thus aimed to pinpoint proportion and clinical characteristics of this kind of patients.

DESIGN AND PATIENTS

We retrospectively evaluated our series of 360 consecutive patients with PHPT, selecting those with all features allowing a correct classification (serum total and ionized calcium, phosphate, creatinine, PTH, 25OHD, urinary calcium, renal and neck ultrasound, MIBI scintiscan, and DEXA at lumbar spine, femoral neck, and distal third of radius). Patients were defined asymptomatic (aPHPT) when bone or kidney was not involved and no hypercalcemic symptom occurred; mild PHPT was defined as aPHPT not meeting updated surgical criteria.

RESULTS

Seventy-five patients among 172 classified as aPHPT had all available data required for surgical evaluation and could be evaluated. Sixty/75 met surgical criteria and the remaining 15 were classified as mild. Mild PHPT patients had lower total and ionized calcium, urinary calcium, and PTH levels than aPHPT meeting surgical criteria, while vitamin D levels and BMD were similar.

CONCLUSIONS

Mild PHPT strictly defined according to the last consensus represents a small subgroup with a less active form of the disease.

Vitamin D supplementation: when and how?

The multiple effects of vitamin D on skeletal and extra-skeletal tissues increased the attention of scientists and public to the possible relationship between hypovitaminosis D and a variety of acute and chronic diseases. However, several points are still largely debated. In particular, the definition of optimal vitamin D status [as assessed by the circulating levels of 25-hydroxyvitamin D (25(OH)D)] remains controversial, and experts still disagree about several related outcomes: how to estimate the prevalence of vitamin D deficiency, when to start treatment, how to reach optimal 25(OH)D levels, which type of vitamin is preferable for supplementation, which dosing strategy is the better option. In this context, a matter of major debate is represented by the measurement of circulating level of 25(OH)D, whose determination is affected by the lack of standardization and by several technical problems. It has been recently hypothesized that free and bio-available, rather than total 25(OH)D, mostly determine its biological action. However, further evaluation of directly measured free 25(OH)D levels is needed, in order to establish its role in research and clinical practice. Finally, it is not yet defined if a threshold of optimal vitamin D status for reducing the risk of extra-skeletal diseases exists. Actually, it is plausible that the desired 25(OH)D level may vary widely, depending on the health outcome in question. However, this topic is uncertain, partly due to the lack of randomized controlled trials assessing the effect of vitamin D supplementation on extra-skeletal end-points.