193. Which one of these is a metal containing Vitamin?
A. Vitamin C
B. Vitamin B1
C. Vitamin B12
D. Vitamin A

Explanation:

Vitamin B12 (Cobalamin):

• Contains the metal cobalt (Co) at its core.

• The cobalt atom is coordinated in a corrin ring, similar to how iron is coordinated in heme.

• It is essential for DNA synthesis, red blood cell formation, and neurological function.

• Found naturally in animal-derived foods, making supplementation important for vegetarians and vegans.

 Other Options:

• Vitamin C (Ascorbic acid): A water-soluble antioxidant, no metal involved.

• Vitamin B1 (Thiamine): Involved in carbohydrate metabolism, no metal.

• Vitamin A (Retinol): A fat-soluble vitamin important for vision and skin health, no metal.

Conclusion:

Vitamin B12 is the only vitamin that contains a metal ion (cobalt), making it unique among all vitamins.

Correct Answer: C. Vitamin B12.