Most such vitamins are fat-soluble, and one's body absorbs them differently than water-soluble nutrients. Vitamins A, D, E, ...
All vitamins are either fat-soluble or water-soluble. The difference between them is how they are absorbed and stored in the body. Both fat and water-soluble vitamins are absorbed during digestion.
The best time to take fat-soluble vitamins like vitamin D, A, and K is with a meal containing fats. You should take water-soluble vitamins like vitamin C, B12, and B6 in the morning on an empty ...