CDR Practice Test – Complete Dietitian Exam Prep

Older adults are particularly vulnerable to toxicity from vitamin A due to several factors related to age, health status, and dietary habits. As people age, their bodies may experience changes in metabolism and liver function, which can affect how vitamins are processed and stored. Vitamin A is a fat-soluble vitamin, meaning it is stored in the body's fatty tissues and liver, and has a higher risk of accumulation when consumed in excess over time.

For older adults, high doses of vitamin A can lead to toxicity, leading to symptoms such as nausea, dizziness, headaches, and even more serious health issues like liver damage or osteoporosis due to its effect on bone health. It's important for older adults to be cautious with the intake of vitamin A, especially from supplements or fortified foods, as their ability to process and eliminate excess amounts may be diminished.

In contrast, vitamins C, D, and K are generally safer with regards to toxicity risk. Vitamin C is water-soluble and excess amounts are usually excreted through urine. Vitamin D, while it can be toxic in excessive amounts, usually requires much higher dosages than what is typically consumed through diet or moderate supplementation. Vitamin K, similarly, has a low risk for toxicity and is well-regulated in the body.

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