Iodine Insufficiency Identified in Pediatric Patient Transitioned to Vegan Diet

Researchers reported a case of endemic goiter in a 23-month-old boy on a restricted vegan diet after discontinued breastfeeding, which may highlight the need for iodine supplementation during pregnancy and lactation, according to recent data.

Olga Yeliosof, MD, from the Goreyb Children’s Hospital in Morristown, New Jersey, presented the data at the 15th International Thyroid Congress and Annual Meeting of the American Thyroid Association. She said that the child was diagnosed with hypothyroidism during an evaluation for macrocephaly.

The child began a vegan diet without iodized salt at 16 months, when he was weaned off of breast milk; prior to weaning, his diet consisted solely of breast milk from his mother, who was actively taking prenatal vitamins. The child’s restricted diet included vegan homemade meals, with restrictions on fish, cow’s milk, and iodized salt.

His exam was only remarkable for macrocephaly and he exhibited no signs of symptoms of hypothyroidism,” Dr Yeliosof said in an email interview with Endocrinology Advisor. “Given the child’s restricted diet, we have considered iodine deficiency as a cause for hypothyroidism in addition to the possibility of autoimmune thyroiditis.”

The mother’s urinary iodine result was 100 mcg/L, indicating iodine sufficiency. The child was treated with 25 mcg of levothyroxine and a multivitamin containing 100 mcg of iodine.Iodized salt was also added to his diet. Dr Yeliosof noted that thyroid function rapidly returned to normal after treatment.

An ultrasound of the child’s thyroid showed a homogenous thyroid without nodules or masses. Because urinary iodine was low and thyroid autoantibodies were within normal range, the researchers concluded the results indicated non-autoimmune thyroiditis.

“We postulated that the hypothyroidism was likely secondary to iodine deficiency,” said Dr Yeliosof. “We observed rapid normalization of thyroid function on levothyroxine likely due to recirculation of iodine pool. “

The researchers discontinued levothyroxine after the child’s urine iodine continued to improve, but kept him on the multivitamin and iodized salt supplementation.

“Upon careful monitoring, we noted mild [thyroid-stimulating hormone] elevation, although free T4 and autoantibody levels remained within normal range and the child remained asymptomatic,” Dr Yeliosof said. “Given the critical role of thyroid hormone in brain development in the first 3 years of life, [the] decision was made to restart levothyroxine until the child is 3 years old. We will consider discontinuing the medication at that time.”

Reference

1. Yeliosof O, Silverman L. Poster 577: Endemic Goiter In A Vegan Toddler In The US. Presented at: Presented at the 15th International Thyroid Congress and 85th Annual Meeting of the American Thyroid Association (ITC/ATA); Oct 18-23, 2015; Lake Buena Vista, Florida.