"vary from person to person": most people or everyone are different?

Dietary needs vary from person to person.

My question is how many people does this sentence address. Does it mean:

i) some people's dietary needs are different.

ii) most people's dietary needs are different.

iii) everyone's dietary needs are different.

1. This is a false comparison, "to vary" is not synonymous with "to differ".

2. If you use the word "different", you need to say different from what. Different from some standard? Different from each other?

3. Dietary needs vary from person to person. There is no quantification mentioned in this statement. It doesn't say all or most or everyone.

The most you can say is that if you go from one person to another, their dietary needs will not necessarily be the same.

I suppose, if you want strict logic, you could say,

Not everyone's dietary needs are the same.

or, if you want to use "different"

There exist at least two people, X and Y, such that the dietary needs of X and Y are different.