Officials said the product -- being recalled by its manufacturer, Trophic Canada Ltd.-- contains an excessive amount of iodine, posing a potential health threat.

Health Canada said excessive iodine exposure can cause either hypothyroidism (underactive thyroid disease) or hyperthyroidism (overactive thyroid disease).

Symptoms of hypothyroidism include weight gain, joint or muscle pain, fatigue, weakness, depression and abnormal menstrual cycles. Eventually it can lead to infertility and heart disease. Hyperthyroidism symptoms include sudden weight loss, rapid or irregular heartbeat, increased sensitivity to heat, sweating, nervousness or irritability. Stroke is one of the most serious complications of hyperthyroidism.

Health Canada said "Trophic Kelp & Glutamic Acid HCl," although not approved for sale in Canada, was available at retailers and pharmacies across the nation and over the Internet.

Consumers with questions can contact the federal agency at 866-225-0709.