I feel itchy on my foot when I use the toilet. I've heard that worms come out or get in from/to body through foot. Is it true? I want to know how to prevent this.

No, this is not true, if your foot itch, it is most likely an infection of some type. *** I have never even heard that before

Itchy foot is usually a fungus (athlete's foot). There are many remedies in your drugstore.

Hook worm larvae can enter through the skin of the foot--they then migrate to the lungs, then the trachea, then are swallowed and enter the GI tract where they become adults. A doctor can check you for hook worms by examining your poop--looking for eggs that the adults shed while in the intestines. Pretty gross stuff. You can avoid them by wearing shoes.

While hookworm larva can enter through the skin and migrate, I wouldn't stress about having parasites simply based on an itchy foot.
Google Cutaneous Larva Migrans and you will see that parasites picked up from the soil in this manner have distinct rashes that go along with itching and irritation.
And they are more prevalent in in tropical and/or unsanitary environments.
Just an itchy foot is more likely a fungal infection.

While hookworm larva can enter through the skin and migrate, I wouldn't stress about having parasites simply based on an itchy foot.
Google Cutaneous Larva Migrans and you will see that parasites picked up from the soil in this manner have distinct rashes that go along with itching and irritation.
And they are more prevalent in in tropical and/or unsanitary environments.
Just an itchy foot is more likely a fungal infection.

Hi~
I wasn't trying to diagnose, I was answering the OP's question specifically.

All settled - it can be either one (or nothing, or something else). As is often the case, we don't even know what part of the world this person lives in or has traveled to.

I know it is because of worm as I can feel the itching only in a tiny area of my foot and that too it happens only when I go to the loo. Thank you all for your suggestions :) I guess as wonderling suggested I can avoid it by simply wearing shoes.