Except for vitamin `B_(12)`, all other vitamins of group `B_(12)` should be supplied regularly in diet. Why?

Explanation

### Step-by-Step Solution:

1. **Understanding Vitamins**: Vitamins are organic compounds that are essential for normal growth and nutrition. They are required in small quantities in the diet because they cannot be synthesized by the body.

2. **Vitamin B Group**: The B vitamins consist of several water-soluble vitamins that play important roles in cell metabolism. These include B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folate), and B12 (cobalamin).

3. **Vitamin B12 Synthesis**: Unlike other B vitamins, vitamin B12 can be synthesized by certain microorganisms present in the human body, particularly in the gut. This means that the body can produce its own supply of vitamin B12.

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