Where are Nutrients Absorbed?
This diagram is from a medical nutrition textbook. You'll see the various sections of the digestive track have specifically assigned absorption points for micro-nutrients
- vitamins and minerals. I've added the notations about the standard lengths of each section of your small and large intestine so you can calculate how much of your intestines have been bypassed based on your own surgical report (from the doctor). I've shaded a section that represents 100-150cm bypass, which is the standard length for most Roux-en-Y surgeries performed today.
Any nutrient that falls within the shaded area of bypass will no longer be absorbed from the food you eat. Those absorption points are designed to grab nutrients from food as the food passes by - but if the food never enters that area again, no nutrients can be absorbed. This is why we must take supplements for the rest of our lives.
i have a question about potassium(and ware it falls on the diagram). how come ppl say it gets absorbed in the small intestines, and here it has it in the large intestines? or is this diagram only for ppl who have had that kind of operation?
ReplyDeleteHello, thank you for all the wonderful information on your site!! Question for you... If the bypassed areas (in gray above) are areas we no longer absorb the listed nutrients, then were/how are they absorbed when taking supplements?
ReplyDelete@Rebecca -- What is represented on this diagram is nutrient absorption from FOOD. The body has to extract vitamins and minerals from food in a specific way along the digestive tract in order for it to be used by cells. HOWEVER, when we take vitamins and minerals in pill form those nutrients are already extracted from food and ready for immediate absorption by the body. Our supplements don't require a specific absorption point with only a few exceptions (such as Vitamin B12 which requires a transporter to be present in the stomach for absorption to happen in the large intestines, so we use sublingual B12 instead of oral). Hope this helps.
ReplyDelete@anon123med -- the diagram here is taken from a medical textbook and illustrates a human digestive tract. We're all the same. The gray shaded part was added by me to show which portion of the intestines are bypassed during RNY gastric bypass surgery. Yes, potassium is indeed absorbed in the large intestine. However, remember that potassium is part of the electrolyte family -- which is calcium, sodium, potassium, magnesium. So if one of those four elements are out of balance, it can throw the rest of them off. So noticed where the others are absorbed - we malabsorb calcium and magnesium but not potassium and sodium. So we have to be very careful to keep a balance and have labs run regularly to make sure the body is getting what it needs.
ReplyDeleteLovely illustration! Thank you!
ReplyDeletewonderful
ReplyDeletewonderful explanation... could you illustrate the situation with mini gastric bypass surgery?
ReplyDelete