Final answer:
In the absence of iron, ferritin becomes apoferritin, which is unable to store iron. This leads to a reduction in ferritin levels in the body, which can indicate iron deficiency and the production of ferritin is also decreased to prevent excess storage without iron.
Step-by-step explanation:
When dietary iron is scarce, the protein ferritin, which normally binds to and stores iron, changes into a form known as apoferritin. Apoferritin lacks iron, as it is essentially ferritin without the iron (Fe) bound to it. In the absence of iron, ferritin cannot carry out its usual function of storing iron, specifically in the form of Fe3+. Instead, the apoferritin molecules remain in the cells in anticipation of iron becoming available again for storage.
Additionally, without sufficient iron, ferritin levels in the blood can decrease, which is often used as a clinical measure of iron deficiency in individuals. The biosynthesis of ferritin is regulated by the amount of iron present in the body. If iron concentration is low, the body reduces the production of ferritin to prevent unnecessary iron storage.