Effect of Different Doses of Oral Cholecalciferol on Serum 1,25(OH)2D in Vitamin D Deficient Schoolchildren.

Data regarding 1,25-dihydroxycholecalciferol in adolescents are limited. We aimed to determine serum levels of this active metabolite of vitamin D and the effects of different doses of vitamin D on its concentration in schoolchildren with high prevalence of vitamin D deficiency. In a previously published randomized double-blind, placebo-controlled trial, 210 subjects, aged 14-20 years, were assigned to 3 regimens of vitamin D treatment: group A (n=70) received 50 000 U oral cholecalciferol monthly, group B (n=70), 50 000 U bimonthly, and group C (n=70), placebo. Serum 25(OH)D, calcium, parathyroid hormone, and bone markers were measured at baseline and after 2 and 5 months of treatment. In the present study, serum levels of 1,25(OH)2D were measured in 97 boys and 95 girls. At baseline, girls had significantly higher concentrations of 1,25(OH)2D than boys (36, IQR: 24, 63 vs. 30, IQR: 15, 57.5 pmol/l; p<0.01). There was no significant correlation between serum levels of 25(OH)D and 1,25(OH)2D in the total population (Spearman rho=- 0.111; p=0.126), boys (Spearman rho=0.008; p=0.941), and girls (Spearman rho=0.036; p=0.729). Also, 1,25(OH)2D values did not change over time in different study groups. Moreover, total and sex-stratified analysis did not show any significant difference between different groups at different times of the study period. In an adolescent population with high prevalence of hypovitaminosis D especially in girls, 1,25(OH)2D values were higher in girls than boys. There was no significant change in 1,25(OH)2D concentrations with different doses of vitamin D.

Effects of different doses of oral cholecalciferol on serum 25(OH)D, PTH, calcium and bone markers during fall and winter in schoolchildren.

BACKGROUND/OBJECTIVES: Controversies surround the actual requirements of vitamin D in adolescents. We aimed to assess the efficacy and safety of different doses of vitamin D in high schoolchildren of Taleghan (latitude 36.5°N) near Tehran. SUBJECTS/METHODS: In a randomized double-blind, placebo-controlled trial, 210 subjects, aged 14-20 years, 105 boys and 105 girls were assigned to three groups; group A (n=70) received 50 000 U oral cholecalciferol monthly (equal to 1600 U per day), group B (n=70), 50 000 U bimonthly (equal to 800 U/day) and group C (n=70), placebo. The study began in November 2007 and continued until April 2008. Serum 25(OH)D, parathyroid hormone (PTH), calcium (Ca) and bone markers were measured. RESULTS: At baseline, girls had significantly lower concentrations of 25(OH)D than boys (19.25±16 vs 40.5±14 nmol/l). Mean 25(OH)D increased from 32±22 to 60±27.5 and 28.25±14.5 to 45.75±24 in groups A and B, respectively (P<0.001); however, it did not change over time in group C (29±18 vs 29±17.5). Increment of mean 25(OH)D was higher in group A than in group B (P<0.01). In all groups, girls had lower concentrations of 25(OH)D than boys (P<0.001). Serum Ca increased and PTH decreased in groups A and B (P<0.001). In group A, osteocalcin (OC) and bone-specific alkaline phosphatase increased (P<0.001), but in group B only OC increased (P<0.001). Urine C telopeptide and Ca did not change in all three groups; no case of hypercalcemia was observed. CONCLUSIONS: Although monthly administration of 50 000 U vitamin D(3) increased serum 25(OH)D significantly, it was apparently not enough to correct vitamin D deficiency, especially in girls.

Changes in calcium, 25(OH) vitamin D3 and other biochemical factors during pregnancy.

INTRODUCTION AND AIMS: Calcium and vitamin D play major roles in calcium homeostasis and skeletal development, especially during pregnancy. This study was conducted to determine changes in calcium, 25 hydroxy [25(OH)] vitamin D3 and other biochemical factors (PTH, osteocalcin, alkaline phosphatase, magnesium, phosphorus) related to calcium homeostasis and bone turnover during pregnancy and compare the values to those of non-pregnant women. MATERIALS AND METHODS: In a cohort study, 48 pregnant women, in their first trimester of pregnancy (12+/-2.7 weeks), from 5 prenatal care centers, and 47 non-pregnant women randomly selected from the Tehran Lipid and Glucose Study (TLGS) population were enrolled. These pregnant women were followed in their second (26+/-1.9 weeks) and third trimesters (37+/-3.2 weeks) of pregnancy. Samples were drawn from June 2002 to March 2003. Including criteria were healthy women with no background of disease. Women using photo protection and calcium and vitamin D supplementation were excluded. A questionnaire was used to obtain demographic information for both groups. Venous blood samples were taken after 12-14 h of overnight fasting to measure serum calcium, phosphorus, magnesium, alkaline phosphatase, PTH, 25 (OH) vitamin D3 and serum osteocalcin levels. The repeated measures analysis of variance and t-test were used for statistical analysis. Data were matched for age and weight in both the case (in the first trimester) and control groups. RESULTS: Significant differences were found in the mean serum levels of osteocalcin and alkaline phosphatase between the three trimesters of pregnancy (p< 0.001). Osteocalcin was significantly higher in the first trimester as compared to second and third trimesters of pregnancy. Alkaline phosphatase was significantly lower in the first trimester as compared to the second and third trimesters of pregnancy and their controls. There was also a significant difference in osteocalcin in the second and third trimesters and alkaline phosphatase in the first and third trimesters of pregnancy in comparison to the control group. The mean values of osteocalcin were 12.7+/-8.5, 8.1+/-6.9, 5.6+/-5.0 and 13.9+/-7.9 ng/ml, respectively, and mean values for alkaline phosphatase were 115+/-38, 125+/-37, 174+/-61 and 134+/-35.0 Iu/l, respectively. In the first trimester, alkaline phosphatase was lower and osteocalcin was higher than in the second and third trimesters. In the first trimester of pregnancy, 20 and 40% of women had 25(OH) vitamin D3 < 10 and < 20 ng/ml, respectively, and 19% of women had serum calcium levels < 8.6 mg/dl. CONCLUSION: 60% of women in the first trimester, 48% in the second and 47% in the third trimester had either severe or moderate vitamin D deficiency. It is recommended that the importance of calcium supplements with vitamin D in pregnant women be stressed for these individuals.

Seasonal variation of serum 25 hydroxy D3 in residents of Tehran.

BACKGROUND AND AIM: vitamin D is essential for bone health. It has been shown that in many communities serum levels of vitamin D can be subject to seasonal variations but so far no study has been conducted on this variable in natives of Tehran. SUBJECTS AND METHODS: 1172 natives of Tehran, 682 women and 490 men, aged 3-69 yr entered the study. Sampling was performed monthly except during Ramadhan, the holy month of Islamic fasting. Serum 25-hydroxyvitamin D (25-OHD) was measured using protein binding assay and levels below 20 ng/ml were determined as vitamin D deficient. RESULTS: serum 25-OHD concentrations showed monthly variations in both sexes but the magnitude of variations was more pronounced in men. The nadir of serum levels in both sexes were seen in December and February, 12 +/- 13 and 14 +/- 14 ng/ml in women, and 28 +/- 16 and 24 +/- 18 mg/ml in men, respectively with the highest values being seen in October; 29 +/- 29 ng/ml in women and 55 +/- 27 ng/ml in men. During the whole period of study the maximum values for women were either equal or less than the minimum values for men. The values for men during summer and winter (31 +/- 17 and 28 +/- 22 ng/ ml, respectively) were significantly lower than the values for spring and fall (38 +/- 27 and 43 +/- 29 ng/ml respectively). In women there was no significant difference in the values of the first three seasons and only the values pertaining to winter were significantly different from the values of fall. CONCLUSIONS: the absence of expected seasonal variations in women coupled with obvious deficiency of vitamin D can be attributed to patterns of life style and also to the traditional clothing of the women of Tehran. Nationwide strategies to improve the vitamin D status of the community, specially for women and children, are highly recommended.

Bilateral testicular enlargement due to adrenal remnant in a patient with C11 hydroxylase deficiency congenital adrenal hyperplasia.

The case of a 15-yr-old boy with C11 hydroxylase deficiency congenital adrenal hyperplasia is reported who was diagnosed and treated as true precocious puberty at the age of 2 yr because of virilization and bilateral testicular enlargement. He later developed hyperpigmentation, hypertension and short stature and because of an increase in testes size he underwent testicular biopsy with the assumption of Leydig cell tumor. With the intake of glucocorticoids his testes size, hypertension and hyperpigmentation improved markedly. We could find only 6 such cases in the literature and have reviewed their clinical and laboratory data. All patients showed the picture of virilization with hypertension. Leydig cell tumor was proposed as the differential diagnosis in all cases except ours. Ultrasonography was able to show testicular adrenal-like tissue in all those in whom the procedure was undertaken. In the 5 patients of whom we could find enough data, 1 responded partially and 4 responded markedly to corticosteroid therapy with shrinkage of testicular tumors. We conclude that clinical findings and US are very important in the early diagnosis of these patients and with adequate treatment most cases show shrinkage in testicular tumors.

Development of true precocious puberty following treatment of a Leydig cell tumor of the testis.

We report a prepubertal boy who developed true precocious puberty following unilateral orchidectomy for the treatment of a Leydig cell tumor.

The effects of iodized oil injection in eu- and hypothyroid iodine deficient girls.

Iodized oil administration has not been effective in restoration of euthyroidism in adolescents and adults, and only partially effective in children aged 4 to 14 years with endemic myxedematous cretinism. Therefore, we studied the effect of iodized oil injection in euthyroid and hypothyroid school girls in an endemic region. Clinical examination and assessment of serum thyroid hormones and TSH were performed before and at 4, 7 and 12 months after intramuscular injection of 480 mg iodine in 54 school girls. Four months after iodized oil injection, T4 and T3 increased from 58 +/- 24 and 2.6 +/- 0.6 to 127 +/- 28 and 3.1 +/- 0.5 nmol/l, respectively. Serum TSH was above 5 mU/l in 45 girls before and in 4 girls four months after injection. None had increased TSH at 7 and 12 months of study. Older girls had lower T4 and higher TSH than younger ones, however, all responded well to iodized oil administration. Serum T3 was above the normal limit of 3.1 nmol/l in 16 subjects. There was no clinical evidence of hyperthyroidism. Mean serum T3 returned to pre-treatment value by 7 and 12 months. TSH response to TRH was subnormal in 5 girls who had increase in either T3 or T4 or both at the end of one year. Injection of iodized oil reverses thyroid function in children and adolescents with hypothyroidism, when the severity of iodine deficiency is not enough to cause thyroid cell atrophy. Transient elevation in serum T3 and/or T4 occurs in many and may last in some at least one year following injection.

Evaluation of pituitary and peripheral tissue markers of thyroid hormone action in an Iranian family with resistance to thyroid hormone.

Resistance to thyroid hormone (RTH), an inherited syndrome of reduced sensitivity to thyroid hormone, is being detected with increased frequency. We report the first family with RTH identified in Iran. Goiter prompted thyroid evaluation, and nonsuppressed TSH associated with high free T4, suggested RTH as the etiology. The mother and all four of her children expressed the RTH phenotype associated with attention deficit and hyperactivity. Detailed clinical and laboratory studies before and following the administration of graded doses of L-T3 demonstrated relatively severe resistance to the hormone at the level of the thyrotrophs and peripheral tissues. Our data underscore the importance of evaluating the changes of various parameters of thyroid hormone action in response to thyroid hormone rather than their measurement at baseline or assessment of absolute levels.

Oestrogen and cortisol producing adrenal tumour.

A 14 year old boy is presented who was admitted to the psychiatric ward because of delirium. He also had gynaecomastia, facial oedema, striae, and hypertension. He was finally proved to have a mixed oestrogen and cortisol producing adrenal tumour which was removed surgically with complete improvement and no relapse.

Frequency-crossing phonon spectrometer techniques.

An ac technique for measuring magnetothermal conductivities using frequency crossing has been developed and shows a 13-fold increase in signal-to-noise ratio over the conventional dc technique. The ac technique employs low-frequency field modulation coupled with phase-sensitive detection and a 45-fold improvement in signal-to-noise ratio may be obtained by modulation over the half-width of the frequency crossing signal. A further increase of approximately 3 would be obtainable by increasing the modulation frequency and overcoming technical problems. The limit of detection and instrument revolution may be as low as 10 in. spins and a few megahertz, respectively.