Question

The iodide ion, usually consumed as potassium iodide, is a dietary mineral essential to good nutrition. In countries where potassium iodide is added to salt, iodine deficiency or goiter has been almost completely eliminated. The recommended daily allowance (RDA) for iodine is 150 ?g/ day. How much potassium iodide (76.45% I) should you consume to meet the RDA?

Short answer

To meet the RDA for iodine, one should consume approximately \( 196.21 \) micrograms of potassium iodide.

Step-by-step solution

Determine the amount of iodine in RDA

The recommended daily allowance (RDA) for iodine is 150 micrograms per day. This is the amount of pure iodine needed.

Calculate the amount of potassium iodide required

Assuming that potassium iodide (KI) is 76.45% iodine by mass, we can set up a proportion to find out how much KI is needed to get 150 micrograms of iodine: \( \frac{76.45}{100} = \frac{150}{x} \)

Solve for x

Cross multiply to solve for x: \( 76.45x = 150 \times 100 \). Now, divide both sides of the equation by 76.45 to solve for x: \( x = \frac{150 \times 100}{76.45} \).

Perform the calculation

Calculate the value of x using the equation from the previous step: \( x = \frac{15000}{76.45} \).

Key concepts

Dietary Minerals

Dietary minerals are natural chemical elements required by living organisms to maintain good health. They play crucial roles in various bodily functions such as bone formation, heart rhythm regulation, and the production of hormones. Unlike vitamins, which are organic compounds, minerals are inorganic and maintain their chemical structure. This means they're not broken down during digestion or destroyed by heat or light, making them stable as they travel through our food supply chain.

Minerals can be categorized into two groups: macro minerals and trace minerals. Macro minerals, like calcium and magnesium, are needed in larger amounts, while trace minerals, such as iodine and selenium, are needed in smaller quantities. Despite their small required amounts, trace minerals are just as essential for health. Iodine, for example, is required for the synthesis of thyroid hormones, which regulate metabolism, growth, and development.

Potassium Iodide

Potassium iodide (KI) is a salt of stable iodine and is often used as a dietary supplement to prevent iodine deficiency. It's especially important in areas where iodine is scarce in the diet due to poor soil conditions. KI provides a simple way to add necessary iodine to a person's diet and is commonly known for its use in iodized table salt.

The body does not produce iodine, so it must be sourced from the diet. Potassium iodide is an effective and reliable source due to its high iodine content. When ingested, it dissolves in the stomach and the iodide ion is absorbed into the bloodstream, while the potassium component contributes to the total dietary intake of potassium, which is also an essential nutrient.

Recommended Daily Allowance

The Recommended Daily Allowance (RDA) is the average daily intake level that is sufficient to meet the nutrient requirements of nearly all (97-98%) healthy individuals in a particular life stage and gender group. The RDA for iodine, set at 150 micrograms per day for most adults, provides enough intake to prevent deficiency diseases such as goiter—a condition characterized by an enlarged thyroid gland.

The RDA is determined by various health organizations and takes into account a safety margin to cover variations in absorption and metabolism among different individuals. It's crucial to aim for the RDA of essential nutrients to support overall health and prevent nutritional deficiencies. However, it's important to note that excessive intake of certain minerals, including iodine, can be harmful, which is why the RDA should not be significantly exceeded without medical supervision.

Iodine Deficiency

Iodine deficiency occurs when there is not enough iodine in the diet, leading to insufficient production of thyroid hormones. It can result in a variety of health problems, the most visible of which is goiter. Other issues include hypothyroidism, and during pregnancy, it can lead to cretinism, a condition that affects the developing fetus leading to severe physical and mental impairment.

Prevalent in regions with iodine-poor soil, such as certain mountainous areas or river valleys prone to flooding, iodine deficiency was a significant problem before the introduction of iodized salt. Efforts to combat this deficiency include the fortification of food with iodine and education on the importance of consuming sufficient iodine. Monitoring iodine intake to ensure that it falls within the recommended parameters is critical to prevent both deficiency and excess.