Dear Dr. Roach: I am 60 years old and generally healthy, but my vitamin D is low (below 20). I took 50,000 IU of vitamin D2 for six weeks, then 2,000 IU of vitamin D3 daily for the past two years. Recently, I started magnesium glycinate, because I read in a journal that it helps D3 get absorbed better in our body and that otherwise, 90% of D3 is passed in stool or urine.
Is that correct? If yes, then is magnesium glycinate the right option for it to absorb easily in our body? R.I.C.
Answer: Vitamin D3 is normally well-absorbed by healthy people without needing any other supplements. Bile is needed for absorption of all D vitamins, as they are fat-soluble, so people with severe obstructive liver disease, as well as people with other malabsorption syndromes, may have difficulty.