Send to

Choose Destination
J Clin Endocrinol Metab. 2014 Aug;99(8):E1454-8. doi: 10.1210/jc.2014-1217. Epub 2014 May 5.

Systematic appraisal of lactose intolerance as cause of increased need for oral thyroxine.

Author information

Department of Medico-Surgical Sciences and Biotechnologies (M.Cel., M.G.S., I.G., C.V., S.C.D.D., N.B., S.C., M.Cen.), "Sapienza" University of Roma, and Endocrinology Unit (M.Cel., S.C.D.D., N.B., L.G., M.Cen.), Azienda Unita Sanitaria Locale Latina, 00040, Latina, Italy.



An increased need for T4 has been described in patients with different gastrointestinal disorders. However, there is a lack of systematic studies assessing the need for T4 in hypothyroid patients with lactose intolerance, a widespread and often occult disorder.


The objective of the study was to assess the replacement T4 dose required in hypothyroid patients with lactose intolerance.


This was a cohort study.


The study was conducted at an outpatient endocrinology unit in a University Hospital.


The replacement T4 dose has been analyzed, from 2009 to 2012, in 34 hypothyroid patients due to Hashimoto's thyroiditis and lactose intolerance and being noncompliant with a lactose-free diet.


An individually tailored T4 dose was measured.


In all patients with isolated Hashimoto's thyroiditis, target TSH (median TSH 1.02 mU/L) was obtained at a median T4 dose of 1.31 μg/kg/d. In patients with lactose intolerance, only five of 34 patients reached the desired TSH (median TSH 0.83 mU/L) with a similar T4 dose (1.29 μg/kg/d). In the remaining 29 patients, the T4 dose was progressively increased and the target TSH (median TSH 1.21 mU/L) was attained at a median T4 dose of 1.81 μg/kg/d (+38%, P < .0001). In six of these patients, other gastrointestinal disorders were diagnosed, and their median T4 requirement was higher (2.04 μg/kg/d; +55%; P = .0032). In the remaining 23 patients with isolated lactose intolerance, a median T4 dose of 1.72 μg/kg/d (+31% P < .0001) has been required to attain pharmacological thyroid homeostasis.


These findings show that lactose intolerance significantly increased the need for oral T4 in hypothyroid patients.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center