Hashimoto’s thyroiditis, hypoparathyroidism and coeliac disease: lessons from a rare association

We present the case of a 36 years old woman, affected by euthyroid Hashimoto’s thyroiditis (HT) from the age of 20. She reported the following symptoms for three years: weight reduction, abdominal pain, alternate constipation and diarrhoea, tiredness, paresthesias and cramps. Biochemical evaluation revealed low iron levels (21 ug/dl, with microcytic anemia) and hypocalcemia (6.6 mg/dl), first attributed to coeliac disease (EMA IgG, AGA IgG-A and tTG IgA positivity; Marsh-Oberhuber 3a/3b type at duodenal biopsy). TSH, PTH and 25-OHD3 were in the normal range. Although the patient was on a gluten-free diet for the second year, cramps persisted and facial spasms and tetanic crises appeared. One year later she came to our attention with severe hypocalcemia (Ca 5.1 mg/dl, Ca++ 0.6 nmol/L) and low PTH (2.5 pg/ml). A diagnosis of primary hypoparathyroidism was made and conventional treatment was started. In the following months, symptomatic hypocalcemia persisted (6.7 mg/dl, Ca++ 0.7 nmol/L), despite the gradual increase of calcium and calcitriol supplements. Gastro-intestinal re-evaluation demonstrated gluten contamination, so as to hypothesize that the scarce dietary compliance had caused persistent malabsorption and had made the hypocalcemia difficult to manage. The observation of these three disorders coexisting in a single patient, never reported by the literature, warns us about the virtually unlimited possibilities of autoimmune disease clustering. Clinicians should be aware of the increased risk of developing additional AIDs in patients with one autoimmune disorder

Predictors of 25(OH)D half-life and plasma 25(OH)D concentration in The Gambia and the UK

Summary: Predictors of 25(OH)D3 half-life were factors associated with vitamin D metabolism, but were different between people in The Gambia and the UK. Country was the strongest predictor of plasma 25(OH)D concentration, probably as a marker of UVB exposure. 25(OH)D3 half-life may be applied as a tool to investigate vitamin D expenditure.  Introduction: The aim of this study was to investigate predictors of 25(OH)D3 half-life and plasma 25(OH)D concentration.  Methods: Plasma half-life of an oral tracer dose of deuterated-25(OH)D3 was measured in healthy men aged 24–39 years, resident in The Gambia, West Africa (n = 18) and in the UK during the winter (n = 18), countries that differ in calcium intake and vitamin D status. Plasma and urinary markers of vitamin D, calcium, phosphate and bone metabolism, nutrient intakes and anthropometry were measured.  Results: Normally distributed data are presented as mean (SD) and non-normal data as geometric mean (95 % CI). Gambian compared to UK men had higher plasma concentrations of 25(OH)D (69 (13) vs. 29 (11) nmol/L; P < 0.0001); 1,25(OH)2D (181 (165, 197) vs. 120 (109, 132) pmol/L; P < 0.01); and parathyroid hormone (PTH) (50 (42, 60) vs. 33 (27, 39); P < 0.0001). There was no difference in 25(OH)D3 half-life (14.7 (3.5) days vs. 15.6 (2.5) days) between countries (P = 0.2). In multivariate analyses, 25(OH)D, 1,25(OH)2D, vitamin D binding protein and albumin-adjusted calcium (Caalb) explained 79 % of variance in 25(OH)D3 half-life in Gambians, but no significant predictors were found in UK participants. For the countries combined, Caalb, PTH and plasma phosphate explained 39 % of half-life variability. 1,25(OH)2D, weight, PTH and country explained 81 % of variability in 25(OH)D concentration; however, country alone explained 74 %.  Conclusion: Factors known to affect 25(OH)D metabolism predict 25(OH)D3 half-life, but these differed between countries. Country predicted 25(OH)D, probably as a proxy measure for UVB exposure and vitamin D supply. This study supports the use of 25(OH)D half-life to investigate vitamin D metabolism