Urgent medical insurance family visit visa-uk

is medical insurance complusory for family visit visa to uk.

My parents are applying tomm at vfs mumbai

They were told by the vfs helpline in mumbai that they need to fill a seperate form if they have medical insurance y/n on applying visa

Please advise
Thx
Navin

"You may therefore wish to ensure that you have health insurance to cover your stay in the UK. " UKBA recommendation .

Given it is so cheap in India it would be well worth taking it out.
Can not see any forms about insurance, Have they traveled to the UK before and had medical treatment and therefore need to show that it was payed for?

They ahve travelled before but no medical treatment at any nhs ....or gp...

It's not mandatory for visitor visa application but recommended for practical purpose should there be any emergency.