I Klinika Chorób Wewnetrznych Slaskiej AM, Katowicach.
The effect of 1,25-hydroxy vitamin D3 on the secretion of TSH was studied in 49 patients with primary hypothyroidism. The vitamin D3 metabolite did not cause any significant changes in the secretion of TSH both basal and stimulated with TRH in patients with untreated hypothyroidism. In those treated with the synthetic L-thyroxine it produced a significant increase in basal TSH secretion.