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BACKGROUND: Low vitamin D levels are a risk factor for osteoporosis. In the Northern hemisphere, a high frequency of low vitamin D levels has been detected. The correction of this deficit is associated with a lower fracture risk. AIM: To measure serum vitamin D levels in postmenopausal women with low bone mineral density. MATERIAL AND METHODS: 25-hydroxyvitamin D levels were measured in 40 postmenopausal women aged 50 to 74 years old, with a spine bone mineral density of less than 2 standard deviation of the values for young individuals. Serum calcium, phosphorus and calcium dietary intake were also measured. RESULTS: Mean serum 25-hydroxyvitamin D levels were 32.2 +/- 12.5 ng/ml. No correlation between vitamin D levels and other measured variables was observed. Using a cutoff value of 15 ng/ml, two women had low 25-hydroxyvitamin D levels. CONCLUSION: In this sample of postmenopausal women, vitamin D deficiency was infrequent.

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We report a man in whom a 15 cm. renal tumor was excised at the age of 49. The pathological examination showed a clear cell carcinoma. Five years later, he presented with headache, vomiting and unilateral palpebral ptosis. Imaging studies showed a sellar tumor with pituitary apoplexy. The tumor was excised and the pathological study disclosed a clear cell tumor, positive for vimentin, cytokeratins AE1 and AE3 and immunohistochemically negative for LH, TSH, ACTH and GH. Considering the similar histopathological features, it was considered as a metastasis of the renal tumor. The patient was supplemented with thyroid, adrenal and gonadal hormones. Seven years later, he presented a new tumor in the remaining kidney, that corresponded to a cystic papillary renal cell carcinoma. Afterwards, he presented a transitional urinary bladder tumor. Mortality associated to renal cell tumors is 90% at 5 years, and pituitary metastases are extraordinarily uncommon.

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Intracellular calcium has been reported to be increased in essential hypertension, and thought to play a role in its genesis through facilitation of vascular smooth muscle contraction. Since hypertension is more prevalent in primary hyperparathyroidism, intracellular calcium may also be increased in this condition. To investigate whether the hyperparathyroid condition, i.e., hypercalcemia and increased PTH per se, could be associated with high intracellular calcium, we measured intracellular calcium in platelets with the Quin-2 AM fluorometric method in 11 normotensive patients with primary hyperparathyroidism, 15 patients with essential hypertension, and 18 normal controls, all matched for age and sex. We repeated the measurements in 9 of the hyperparathyroid patients after successful surgery. We found that intracellular calcium was higher in normotensive patients with primary hyperparathyroidism than in normal controls (198 +/- 24 vs 113 +/- 11 nM, p < 0.05), but lower than in patients with essential hypertension (198 +/- 24 vs 286 +/- 38 nM, p < 0.05). Successful removal of a parathyroid adenoma decreased intracellular calcium from 215 +/- 22 to 116 +/- 19 nM, (p < 0.01). In the patients with primary hyperparathyroidism, intracellular calcium was strongly correlated with the levels of PTH (r = 0.87, p < 0.01), but not with the total serum calcium levels (r = 0.04, NS). The decrease in intracellular calcium after parathyroidectomy was also strongly correlated with the decrease in PTH (r = 0.84, P < 0.01), but not with the decrease in total serum calcium (r = 0.16, NS). In the patients with essential hypertension, intracellular calcium correlated well with systolic (r = 0.69, p < 0.01), diastolic (r = 0.76, p < 0.01) and especially mean arterial pressure (r = 0.86, P < 0.01). There was no correlation between blood pressure and intracellular calcium in the patients with primary hyperparathyroidism. We conclude that normotensive patients with primary hyperparathyroidism, as well as patients with essential hypertension, can have increased concentrations of intracellular calcium in platelets. The correction of the hyperparathyroid condition normalizes intracellular calcium concentration. The close correlation between PTH and intracellular calcium suggests that PTH may act as a ionophore for calcium entry into cells. Whether the increased levels of intracellular calcium may reflect a pre-hypertensive condition in normotensive patients with primary hyperparathyroidism remains to be determined.

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The variations in plasma levels of TSH, T4, T3, and rT3, during the pubertal period, were studied in 647 school students from the urban area of Santiago in Chile (47% males and 53% females) with ages ranging between 7.5 and 15 yr. The subjects were grouped by age in consecutive intervals of 6 months each, and pubertal development was determined in every subject. TSH showed a significant increase, reaching a peak in the 9- to 9.5-yr interval. The same was found for T3 and T4, which reached a peak by 10 and 11 yr. The T4/T3 ratio did not show any significant variation with age. After 9.5 yr, a decrease in rT3 and increase in the T4/rT3 ratio was found. The TSH peak preceded the onset of clinical pubertal development, while the T3 and T4 peaks coincided with this onset. The variations in rT3 suggest an increase of peripheral conversion of T4 to T3. These transient events, not described until now, could be termed thyroidarche and could have a significant effect on pubertal growth and development.

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