Endocrine Abstracts

Background: Iodine deficiency is the most common cause of acquired hypothyroidism worldwide. Incidence of iodine deficiency may be rising due to usage of vegan diet.

Case presentation: We present siblings aged 2.5 years boy and 6 years old girl from family who are strict vegans. Both children have been on vegan diet since birth. Boy attended hospital urgently due to significant concerns about hypothyroidism. His TSH level 2 months before admission was 187 mIU/l and fT4 was < 4 pmol/l. At the hospital admission his weight was between the 2nd and 4th centile and his height was below the 0.2nd centile. He was diagnosed with iron deficiency and vitamin B12 deficiency and hypothyroidism 2 months before admission and parents stated giving him multivitamins with iodine and iron. In terms of thyroid related symptoms, apart from growth the main issue was hair thinning and loss, which parents have noticed over the past few months. Energy levels seemed appropriate. He was not having any skin or nail manifestations. Developmentally no concerns at all and he was bilingual and his speech was appropriate for his age. His motor development had not been a concern either. At the admission in his bloods test he was still iron deficient, but his thyroid function was normal with TSH of 0.44 mIU/l and fT4 15.2 pmol/l. His 6 year old sister was referred to endocrine clinic due to goitre, which parents noticed at the age around 2½ years old. She also was found to have subclinical hypothyroidism with slightly elevated TSH with normal FT4 (FT4: 16 pmol/l, TSH: 7.04 miu/l) and an enlarged thyroid gland on ultrasound scan. Following this the family started both children on vitamin supplements with iodine. Both children were referred to dietician to help family balance their diet.

Conclusions: This case highlights the risk for iodine deficiency in children on a vegan diet and that it can lead to acquired hypothyroidism and goitre. Doctors should be aware of the danger of not supplementing with iodine in a vegan diet children.