Did you even read the thread before you posted that itson?
When you have a child who won't eat, who refuses food, whose food choices dwindle down to the bare minimum, who will literally starve themselves, you feed them whatever it is that they will eat because some less than optimum calories are better than absolutely no calories at all.
FTI, vitamin supplements are recommended by professionals. DS dietician recommended a specific multivitamin which meets all of the recommended daily vitamins and minerals and a minimum of two cups of whole milk a day. Luckily DS will tolerate both of these things at the moment, under duress, but if he refused when older I wouldn't be able to pin him down and force it down him.