Her fra en posting fra idag på thyroid.about.com forumet UK:

34 of 34 Posted 6:31 PM Msg 3302.34 reply to 3302.24
From milenium9uk
Advances in Vitamin D nutritional physiology since publication of the DRIs in 1997 are briefly summarized. Available data indicate that (1) Vitamin D's canonical function, optimizing intestinal calcium absorption, is fully expressed at serum 25-hydroxyvitamin D (25OHD) concentration of 80 nmol/L; (2) elevated parathyroid activity, typical of aging populations, is minimized at the same 25OHD value and (3) osteoporotic fractures are reduced when serum 25OHD is raised to near 80 nmol/L. Depending upon starting value, achieving 25OHD concentrations of 80 or higher may require a daily oral intake of 2200 IU (55 µg) or more in addition to prevailing cutaneous inputs. The tolerable upper intake level (TUIL), currently set at 2000 IU (50 µg)/day, is too low to permit optimization of Vitamin D status in the general population. Actual toxicity is not seen below serum 25OHD values of 250 nmol/L, a value that would be produced only at continuing oral intakes in excess of 10,000 IU (250 µg)/day.

Keywords: Vitamin D; 25-Hydroxyvitamin D; DRI; TUIL; Calcium absorption; Parathyroid hormone; Osteoporotic fractures; Bone mineral density

http://dx.doi.org/10.1016/j.jsbmb.2005.06.022

Leate engang noe ligniende på 70-tallet, at vi får for lite vitamin D og at den tillatte daglige dosen var alt for liten.
Her sies det at man må få i seg mere enn den anbefalte mengden hver dag.