Is Kelp or Dulse Higher in Iodine?

Iodine is an important nutrient for the proper function of the thyroid. Too much or too little iodine may impact thyroid balance, metabolism and energy levels. One type of food that can be helpful in increasing iodine levels is seaweed. In particular, both dulse and kelp are high in this nutrient. If you are dealing with thyroid issues, it is important that you work with your doctor to determine thyroid function. Do not self-medicate with dulse or kelp, or any other food.


Kelp is a seaweed that is harvested from the ocean. In her book, Prescription for Dietary Wellness, certified nutrition consultant Phyllis A. Balch notes that kelp is a brown algae that thrives in cooler water at depths of nearly 50 feet, and can be as long as 1,500 feet 1. Kelp contains many minerals and trace minerals, including calcium, copper, magnesium and iodine. It is also high in protein and fiber, while being low in calories and fat-free. Kelp is sometimes purported to help with thyroid function due to its high iodine content. According to the book, Comprehensive Handbook of Iodine: Nutritional, Biochemical, Pathological and Therapeutic Aspects, edited by Victor R. Preedy, a 1-gram serving of kelp contains 1,820 micrograms of iodine 4.


Dulse in another seaweed that comes from the ocean and has a high nutritional content. Balch notes that dulse is a native sea vegetable harvested in the North Atlantic and Pacific Northwest, and has a strong, distinctive flavor and chewy texture. Rich in protein, potassium, iron, vitamin K and iodine, dulse may be helpful with blood clotting and also with increasing thyroid function, as iodine is an important component of the the thyroid. A 1-gram serving of dulse contains 72 micrograms of iodine -- much less than the 1,820 micrograms in kelp.


Even though dulse has a lower iodine content than kelp, according to Dr. Gabriel Cousens in his book, Spiritual Nutrition, dulse may be a better choice for supplying iodine 2. This is due to the fact that dulse has a bit more manganese than kelp, and manganese is an important nutrient for the absorption and function of iodine in the system. The synergistic patterns of minerals are important, notes Cousens, because the minerals must work together in a way that the body can properly use them.


If you suffer from hyperthyroidism, the jitters or sleeplessness, do not eat large amounts of either dulse or kelp, as they may increase these effects. Naturopathic doctor Asa Hershoff notes in her book, Herbal Remedies, that kelp and dulse should only be used under medical supervision if you suffer from thyroid disease, as they may worsen some conditions 3. Also, avoid these seaweeds if you are pregnant or breastfeeding.