My grandfather has been in the hospital for 5 months. His body isnt retaining any nutrients from the food he has been eating. He has lost an incredible amount of weight and can't even stand up on his own. What can be wrong that his body isnt taking in the nutrients given to him from vitamins and food?
There are a lot of other reasons for weight loss. Cancer will often cause rapid and serious weight loss because the cancer cells grow faster than normal cells and require more calories plus nutrients to support their fast growth. If he has cancer then that could be the reason why the food he eats is not helping him.
Is he on medication? Some medicines reduce the appetite and make people feel too sick to eat. And, unfortunately, sometimes people just don't feel like eating . The longer they don't eat the weaker they start to feel. The weaker they feel the less they want to eat.
You and your grandfather are in my prayers. I hope they can find out what's wrong and help him feel better.