Quick Answer. The effects of caffeine start within 10 minutes after it is consumed, according to ScienceDaily. However, caffeine requires 45 minutes to reach its maximum concentration in the blood. Continue Reading.
The heart, blood, and blood vessels are the three structural elements that ... These nutrients enter the bloodstream by passing through the walls of the intestine.he heart, blood, and blood vessels are the three structural elements that ... These nutrients enter the bloodstream by passing through the walls of the intestine.
Normally, foods are digested and nutrients (proteins, carbohydrates, fats, vitamins, and minerals) are absorbed into the bloodstream mainly in the small intestine. Malabsorption may occur if a disorder. Interferes with the digestion of food. Interferes with the absorption of nutrients.