Iodine in Fruits: An Overview
Fruits are an essential part of a balanced diet, although they are not a significant source of iodine. The mineral content in plant-based foods, including fruits, depends on the soil they are grown in. This causes variations in iodine levels, even in the same type of fruit.
Fruits With Trace Amounts of Iodine
Some fruits contain small amounts of iodine. These levels are low and inconsistent. You should not rely on them to fulfill the daily recommended intake of 150 mcg for adults.
Fruits that contain trace amounts include:
- Strawberries: May contain around 13 mcg of iodine per 100 grams, but other data indicates a much lower content of 1-3 mcg,.
- Prunes: Dried plums, or prunes, have been noted to contain around 5-13 mcg of iodine per serving, with the amount varying by portion size,.
- Cranberries: Approximately 2 mcg per 100 grams have been measured in cranberries.
- Bananas: A medium-sized banana has 2-3 mcg of iodine, which does not substantially contribute to a person's daily needs,.
- Other fruits: Trace levels (1-2 mcg/100g) have been detected in fruits like pineapple, kiwi, and oranges, but these quantities are extremely small.
Impact of Soil Quality on Iodine
The low and variable iodine content in fruits and vegetables is linked to soil geochemistry. Iodine is not evenly distributed across the Earth's soil. Crops grown in areas with low soil iodine levels have very little of the mineral. Coastal areas often have higher iodine levels in their soil.
Scientific research has explored biofortification to enrich crops with iodine through special fertilizers. Without intervention, the natural concentration in fruits is typically insufficient for dietary needs.
Reliable Dietary Sources of Iodine
Other food groups are more effective at meeting the recommended daily intake. These sources contain higher iodine levels and are less affected by environmental factors.
- Seaweed: This marine vegetable is one of the richest natural sources of iodine. Kelp, nori, and wakame are excellent choices.
- Seafood: Ocean fish and shellfish absorb iodine from seawater. Cod, shrimp, and tuna are excellent sources.
- Dairy Products: Milk, yogurt, and cheese are good sources due to iodine-containing disinfectants and supplements in cattle feed.
- Iodized Salt: The most common and reliable source of iodine for many households. A quarter teaspoon provides a significant portion of the daily recommended intake.
- Eggs: The yolk of one large egg contains a notable amount of iodine.
Comparison Table: Iodine in Fruits vs. High-Iodine Foods
| Food Item (approx. 100g) | Iodine Content (mcg) | Percent of Adult RDI* | Primary Source Category |
|---|---|---|---|
| Strawberry | 1–13, | <1%–9% | Fruit |
| Banana | 2 | 1.3% | Fruit |
| Apple | <0.5 | <1% | Fruit |
| Cod | 87 (per 75g) | 58% | Seafood |
| Milk (1 cup) | 52–62 (per 250ml) | 35%–41% | Dairy |
| Iodized Salt (1/4 tsp) | 78 | 52% | Fortified Food |
| Seaweed (Nori, 100g) | 116 | 77% | Sea Vegetable |
*Based on a recommended daily intake of 150 mcg.
Conclusion
Fruits are not a primary source of iodine. The mineral content is too low and variable to meet daily requirements. A diet incorporating foods rich in iodine—such as seaweed, seafood, and dairy—is essential. Using iodized table salt is a simple way to prevent deficiency. For a vegan or restricted diet, consider iodine-fortified products or supplements after consulting a healthcare professional. For more information, refer to the National Institutes of Health(https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/). By diversifying your diet, you can easily obtain the necessary amount of this crucial mineral for optimal thyroid function and overall health.
