Which Vitamin is excreted in urine
**Core Concept**
Vitamin excretion in urine is an essential aspect of renal physiology and pharmacology. The kidneys play a crucial role in regulating the body's vitamin levels by excreting excess amounts in the urine.
**Why the Correct Answer is Right**
Vitamin B12, also known as cobalamin, is excreted in the urine. This occurs primarily through glomerular filtration and subsequent tubular secretion. The kidneys filter Vitamin B12 from the blood and excrete it in the urine, helping to maintain a balance of this essential nutrient in the body.
**Why Each Wrong Option is Incorrect**
**Option A:** Vitamin A is primarily excreted in the bile and feces, not in the urine.
**Option B:** Vitamin D is metabolized in the kidneys but not excreted in the urine; instead, it is reabsorbed and activated in the body.
**Option C:** Vitamin E is primarily excreted in the feces, not in the urine.
**Clinical Pearl / High-Yield Fact**
The kidneys play a vital role in maintaining vitamin balance, and impaired renal function can lead to vitamin deficiencies. It's essential for clinicians to consider renal function when evaluating patients with vitamin deficiencies.
**Correct Answer: B. Vitamin B12**