Hi Mary Vanderlaan, Thank you for the post. This has increased implications on those suffereing HD in our group. Short bowels impair the absorption of many vitatmins. For example with no large Intestine (Colon) the body does not get B12 and shots are necessary monthly. Higher doses of magnesium will aggravate diarhea which is already an issue for many HD people. I have posted your post with Dr. Harper's letter to the Haddad syndrome - CCHS group page. I am also posting delivery options for these vitamins that might be HD friendly and avoid the diarhea issue. Magnesium can be delivered transdermally. Actions are being taken as we speak in our family and some dots are being connected on how to better our medications and diet plan. Thank you and Dr Harper for good actionable information.