The Vitamins & Minerals Found in Kelp

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Kelp, a brown leafy edible seaweed that grows along colder coastlines, has been used for thousands of years in traditional medicine to treat a variety of health issues. It started to gain interest as a supplement in the 1980s when sea vegetables became a popular form of supplementation. As with any supplement, discuss using kelp with your doctor.

Traditional Use

Kelp has been used in Asian cooking for thousands of years. In Chinese is is called kunbu and is one of the main seaweeds used in the Chinese medicine. Traditional Chinese medicine uses kelp to treat enlarged thyroid glands, swelling, cysts, liver problems, tumors and phlegm. In the 18th century, when kelp's iodine content was discovered, conventional medicine used it to treat goiter, an enlarged thyroid, typically caused by iodine deficiency in the diet.


In 2 tbsp.,1/8 cup, of fresh, raw kelp there is 0.3 mg vitamin C, 0.005 mg thiamin, 0.015 mg riboflavin, 0.047 mg niacin, 0.064 mg pantothenic acid, 18 mcg folate, 1.3 mg choline, 1 mcg vitamin A, 0.09 mg vitamin E and 6.6 mcg vitamin K. To put this in perspective, comparing the amounts to the Recommended Daily Allowances of an adult male, 2 tbsp. of raw kelp provides 0.3 percent vitamin C, 0.42 percent thiamin, 1.2 percent riboflavin, 0.3 percent niacin, 1.3 percent pantothenic acid, 4.5 percent folate, 0.2 percent choline, 0.1 percent vitamin A, 0.4 percent vitamin E and 5.5 percent vitamin K.


In 2 tbsp., 1/8 cup, of fresh, raw kelp there is 17 mg calcium, 0.28 mg iron, 12 mg magnesium, 4 mg phosphorous, 9 mg potassium, 23 mg sodium, 0.12 mg zinc, 0.013 mg copper, 0.02 mg manganese, and 0.1 mcg selenium. Comparing these amounts to the Recommended Daily Amounts of an adult male, 2 tbsp. fresh, raw kelp provides 1.7 percent calcium, 3.5 percent iron, 3 percent magnesium, 0.6 percent phosphorus, 0.2 percent potassium, 1.5 percent sodium, 1 percent zinc, 1.4 percent copper, 1 percent manganese, and 6.7 percent selenium. The mineral kelp is known for is iodine because 2 tbsp. raw kelp contains between 500 and 8,000 mcg of iodine, which is 300 percent to 5,333 percent of the recommended amount for an adult male.

Kelp as a Supplement

The high natural iodine content of kelp makes it a natural food or supplement to combat iodine deficiency. Because the amount of iodine varies so much in kelp, be aware you could experience iodine toxicity if you eat too much. Two or three servings a week should provide ample iodine to the diet, notes Kelp is marketed as a weight loss aid by apparently helping to reduce cravings, and there are claims that it can help prevent cancer and other diseases as its high vitamin and mineral content help the body to regenerate, reports the American Cancer Society. At this time, there is no reliable clinical evidence to prove these claims.