macOS $ locale returns some empty fields

LANG=
LC_COLLATE="C"
LC_CTYPE="UTF-8"
LC_MESSAGES="C"
LC_MONETARY="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_ALL=
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
You have seen a copy of my $locale command.
I know it's not an overwhelming problem but I'd like to fix this unusual behaviour.
I've noticed this after using brew to install gtk+3 and building the first example program. Here is the warning for program's execution:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Gtk-WARNING **: Locale not supported by C library.
Using the fallback 'C' locale.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

leman said:

Why is this a 'problem'? I am rather surprised that your locale is set to C instead of en_US.UTF-8 or friends. You can also read this (potential fixes included): http://stackoverflow.com/questions/7165108/in-osx-lion-lang-is-not-set-to-utf8-how-fix

Click to expand...

It's not that the warning is such a big problem per se. However I've been taught the less the warnings the better the code, to ignore warnings only if I know there is no harm with them.
Enough blabbering.. thank you very much, that link made my day.
Oddly the reason for those uncommon values are to be found inside the man locale:"that if LANG is unset it will be set to 'C', moreover every other unset field will inherit LANG's value."

PS: Do I have to set the thread as SOLVED? if so, please hint me.