All are true about vitamin E except –
**Core Concept**
Vitamin E is a fat-soluble vitamin that plays a crucial role in protecting cells from oxidative damage by neutralizing free radicals. It is also involved in maintaining the integrity of cell membranes and supporting immune function. Vitamin E deficiency can lead to neurological problems, impaired immune function, and increased susceptibility to infections.
**Why the Correct Answer is Right**
Vitamin E is known for its antioxidant properties, which help to prevent the formation of lipid peroxides in cell membranes. It achieves this by scavenging free radicals, thereby protecting cells from oxidative damage. Vitamin E also plays a role in the regulation of immune function and has been shown to have anti-inflammatory effects. The recommended daily intake of vitamin E varies by age and sex, but it is generally around 15 mg per day.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because vitamin E does not play a direct role in the regulation of blood pressure. While vitamin E may have some indirect effects on blood pressure due to its antioxidant properties, it is not a primary regulator of blood pressure.
**Option B:** This option is incorrect because vitamin E does not have a significant effect on the absorption of calcium. Vitamin D and vitamin K are more closely related to calcium absorption, whereas vitamin E is primarily involved in antioxidant functions.
**Option C:** This option is incorrect because vitamin E is not directly involved in the regulation of thyroid hormone levels. While vitamin E may have some indirect effects on thyroid function due to its antioxidant properties, it is not a primary regulator of thyroid hormone levels.
**Clinical Pearl / High-Yield Fact**
Vitamin E deficiency is more common in individuals with fat malabsorption syndromes, such as celiac disease or Crohn's disease. It is also more common in individuals with liver disease, as the liver plays a critical role in vitamin E metabolism.
**Correct Answer:** D.