Vitamin D levels decreasing as supplements are increased?

[Guest guest]

Hi folks,

A friend with colitis is having problems with her Vitamin D levels. Her GI doc

increased her Vitamin D supplement twice now (up to 1,000 IUs once a week I

believe) with a resultant decrease in serum Vitamin D levels (26 to 24 down to

22). He has now recommended switching to Vit D3 supplement, which she recently

began. She also has lactose intolerance, which doesn't help but she consumes

fish regularly. Any suggestions about what might be going on other than the

obvious intestinal malabsorbtion?

Thanks,

Ruth Craig, MS RD