Nutmeg
Nutmeg is one of the best spices for increasing absorption especially in the small intestine. Adding a bit of cardamom and ginger work synergistically with nutmeg. It reduces Vata in the colon that can manifest as diarrhea and is one the best medicine for calming the mind. Taking 500mg ( that is about 1/10 of a teaspoonful in a warm drink before going to bed has been found to calm the mind and promote sleep. However taking too much can have a dulling effect on the mind. (source - The Yoga of Herbs - by Frawley and Lad)