Generally speaking, how much of all vitamins specifically does my body need daily and how of the vitamins does my body absorb?

Depends on person.: It varies between individuals depending on the health of one's digestive system, which requires adequate stomach acid, small intestine enzymes, and good bacteria (e.g., acidophilus) in gut. Consider a nutritional test where nutrient concentrations are measured at cellular level (e.g., spectracell). Check rda for minimum requirements. Use professional sources for best quality products and results.