There has recently been a huge number of publications concerning various aspects of vitamin D, from the physiological to therapeutic fields. However, as a consequence of this very fast-growing scientific area, some issues still remain surrounded by uncertainties, without a final agreement having been reached. Examples include the definitions of vitamin D sufficiency and insufficiency, (i.e., 20 vs. 30 ng/mL), the relationship between 25-hydroxyvitamin D (25(OH)D) and parathyroid hormone, (i.e., linear vs. no linear), the referent to consider, (i.e., total vs. free determination), the utility of screening versus universal supplementation, and so on. In this review, the issues related to vitamin D supplementation in subjects with documented hypovitaminosis, and the role of vitamin D in cancer will be concisely considered. Daily, weekly, or monthly administration of cholecalciferol generally leads to essentially similar results in terms of an increase in 25(OH)D serum levels. However, we should also consider possible differences related to a number of variables, (i.e., efficiency of intestinal absorption, binding to vitamin D binding protein, and so on). Thus, adherence to therapy may be more important than the dose regimen chosen in order to allow long-term compliance in a sometimes very old population already swamped by many drugs. It is difficult to draw firm conclusions at present regarding the relationship between cancer and vitamin D. In vitro and preclinical studies seem to have been more convincing than clinical investigations. Positive results in human studies have been mainly derived from post-hoc analyses, secondary end-points or meta-analyses, with the last showing not a decrease in cancer incidence but rather in mortality. We must therefore proceed with a word of caution. Until it has been clearly demonstrated that there is a causal relationship, these positive “non-primary, end-point results” should be considered as a background for generating new hypotheses for future investigations.

Objective: The prevalence of abdominal aortic calcification (AAC) in primary hyperparathyroidism (PHPT) is unknown. We assessed both prevalence and severity of AAC in PHPT postmenopausal women.Methods: In this study 70 PHPT postmenopausal women and 70 age- and sex-matched controls were enrolled. Each participant underwent biochemical evaluation, lateral spine radiograph, bone mineral density (BMD) measurement (lumbar, femoral, radial sites), and kidney ultrasound. Lateral lumbar films were analyzed in the region of L1–L4 vertebrae and the Kauppila score (a semi-quantitative grading system) was used to assess the severity of AAC.Results: There were no differences regarding demographic and cardiovascular risk factors in the two groups. PHPT patients had higher prevalence of kidney stones (30% vs 7%,P=0.0008) and lower radial BMD values (0.558±0.071 vs 0.588±0.082 g/cm²,P<0.05) compared with controls. PHPT patients showed higher prevalence of AAC (31 vs 18,P=0.03), with more severe calcifications (Kauppila score 7.35±6.1 vs 5.05±3.5,P=0.007). PHPT patients with AAC were older and had been suffering from the disease for a longer period compared with those without ACC. Moreover, PHPT patients with severe AAC had mean higher serum parathyroid hormone levels compared with patients with moderate or mild calcifications. In PHPT patients with AAC, multiple regression analysis, adjusted for age and years since diagnosis, showed that only parathyroid hormone significantly correlated with Kauppila score.Conclusion: We found a higher prevalence and severity of AAC in PHPT related to parathyroid hormone effect.

Objective: Hypercalcemia may induce arrhythmias. There are no data on the prevalence of arrhythmias in primary hyperparathyroidism (PHPT) in daily life. Aim of the study was to investigate both the prevalence of arrhythmias in patients with PHPT compared to controls and the impact of parathyroidectomy, evaluated by 24-h electrocardiogram (ECG) monitoring.Design: This is a randomized study.Methods: Twenty-six postmenopausal women with PHPT and 26 controls were enrolled. PHPT patients were randomized to two groups: 13 underwent parathyroidectomy (Group A) and 13 were followed up conservatively (Group B). After 6 months, patients were studied again. Each patient underwent mineral metabolism biochemical evaluation, bone mineral density measurement, standard ECG and 24-h ECG monitoring.Results: PHPT patients showed higher calcium and parathyroid hormone compared to controls and a higher prevalence of both supraventricular (SVBPs) and ventricular premature beats (VPBs) during 24-h ECG monitoring. Groups A and B showed no differences in mean baseline biochemical values and ECG parameters. Mean value of QTc in PHPT groups was in the normal range at baseline, but significantly shorter than controls. A negative correlation was found between QTc and ionized calcium levels (r = −0.48,P < 0.05). After parathyroidectomy, Group A had a significant reduction in SVPBs and VPBs compared to baseline and restored normal QTc. Group B showed no significant changes after a 6-month period.Conclusions: The increased prevalence of SVPBs and VPBs is significantly reduced by parathyroidectomy, and it is mainly related to the short QTc caused by hypercalcemia.