Do my NHS benefits extend to my kids in college in the US?

My wife and I are living and working here in the UK, but our two kids have returned to the US for college. Do our NHS benefits extend to children studying in the US? I think the answer is no, but I have not been able to find the answer on the NHS site.

No.  The NHS isn't "coverage" like insurance is, so it is only valid in the UK.  Even if it were coverage, your non-UK citizen, non-visa-holding, over-18 children wouldn't be eligible. 

The NHS is a public service available only to people who are physically present in the UK. Rather than being like US medical insurance/coverage, it's best to think of it more like other universal public services, like the police, fire service or public school system - you can only use these services when you live in the country/area where they are offered.

You wouldn't expect your children to be helped by the UK police, UK fire service or the UK state school system while they are in the US... and the same goes for the NHS.

UK citizens who are not living in the UK cannot be treated by the NHS either - I'm a UK citizen who lived in the US as an international student a couple of years ago and I still had to purchase US health insurance to cover medical care while I was living there.