Daily Iodine Requirement and Natural Iodine Sources

Daily Iodine Requirement and Natural Iodine Sources

As is well known, the seas are among the most important natural sources of iodine. Crystal rock salts are natural minerals formed when ancient seas evaporated and their salts settled approximately 250 million years ago. The crystal rock salt products produced by Tuzcu Baba Çankırı Kaya Tuzu İşletmesi contain naturally occurring iodine; iodine is not added later by industrial methods. For this reason, our product labels state “no iodine added” rather than “iodine-free.”

Iodine is an important nutrient required for the normal growth and development of humans and animals. It is present in the human body only in very small amounts and is obtained through the food we eat and the water we drink. A large part of the iodine in the body is found in the thyroid gland and is used in the production of thyroid hormones. These hormones are involved in normal growth, mental development, body temperature and energy production.

Iodine found naturally in soil and water passes into foods. Mountainous and heavily eroded soils can be poor in iodine, and the source article states that soils in many regions of Türkiye are iodine-poor for this reason.

The original archive article criticizes the policy of adding iodine to refined table salt. It argues that, while iodine is added for nutritional reasons, refined salts may also contain substances used to improve flow, reduce moisture and prevent caking, and it names aluminium silicate and similar processing aids as examples. The article claims that such refined products may be undesirable for the body and associates them with a number of health problems. It also notes that iodine in iodized salt can be lost when the salt is left exposed to light and air. These statements reflect the claims made in the original source article.

The article says that further details can be found in its related discussion of refined salt. It also argues that iodine needs can be met through natural dietary sources and warns against assuming that iodized salt alone is sufficient in every situation. It notes that some conditions, including goiter and hypothyroidism, may require hormone treatment.

Nutrition specialists are cited as recommending about 150 micrograms of iodine per day for adults, while pregnant and breastfeeding women may need up to about 250 micrograms per day.

Examples of iodine in foods

Foods containing iodine

Seafood: Fish, especially saltwater fish, can be rich in iodine and may be consumed as a dietary iodine source. The article lists tuna, haddock, cold-water fish and deep-sea fish among relatively iodine-rich fish. Shrimp and other shellfish are also cited as iodine sources. It states that 200 grams of fish may provide at least half of daily iodine needs.

Vegetables: The article lists spinach, soybeans, turnips, chard, squash, dried beans and garlic among vegetables with relatively high iodine content. It also notes that these foods may contribute vitamins and antioxidants.

Fruit: Fruit is generally not considered a major source of iodine, and only a few fruits contain notable amounts. The article mentions strawberries as an example and states that six or seven strawberries may provide about 8% of daily iodine needs.

Yogurt, milk and cheese: Milk and dairy products are described as useful iodine sources. The source gives approximate figures of about 60% of daily iodine needs from a bowl of yogurt, 40% from a glass of milk and 20% from one egg.

Diet and cooking considerations

The article also discusses eating and cooking habits. It says that even when total iodine intake is adequate, excessive consumption of goitrogenic foods—foods that can interfere with thyroid hormone function—may reduce iodine utilization. It gives kale, radish, turnip and Brussels sprouts as examples and recommends avoiding excessive consumption.

As an example, the article points to the Eastern Black Sea region, where goiter has historically been common. It associates this both with frequent consumption of kale, which it says can interfere with iodine uptake, and with heavy rainfall that can reduce iodine content in the soil.

The article further states that cooking may reduce the iodine content of foods because iodine is volatile. It recommends consuming foods fresh and avoiding unnecessarily long boiling, frying and grilling times in order to reduce iodine and mineral losses during cooking.

Finally, it recommends adding natural Çankırı rock salt after cooking is complete.

Bilal ÖZKAN