Key clinical recommendation	Label	References
Daily vitamin D supplementation of 800 to 1,000 IU is a reasonable dose for adults.	C	2,9,10
Levels of 25-hydroxyvitamin D should be maintained above 32 ng per mL (80 nmol per L) to maximize bone health.	C	11
In patients with severe vitamin D deficiency (serum levels of below 8 ng per mL with hypocalcemia), 50,000 IU of vitamin D should be given daily for one to three weeks, followed by weekly doses of 50,000 IU.	C	2,7
After repletion of body stores, 800 IU of vitamin D daily or 50,000 IU of vitamin D once or twice monthly is adequate maintenance therapy.	C	2,10
Patients with no sun exposure, malabsorption, or those taking antiepileptic drugs may require larger maintenance doses of vitamin D (i.e., up to 50,000 IU one to three times weekly).	C	2,7
In critically ill patients, albumin-adjusted calcium levels underestimate true or ionized hypocalcemia. Therefore, measured ionized calcium levels are recommended, particularly in patients who are being treated in an intensive care unit.	B	12
If calcium supplementation alone fails to maintain normal serum levels, the patient is vitamin D deficient or resistant and may benefit from a trial of calcitriol (Rocatrol).	C	5
If the vitamin D deficiency is severe, the patient will require 90 mmol per L in the first 24 hours: 6 mL of K2PO4 added to each liter of fluid and given at 200 mL per hour (1 mL of K2PO4 is equal to 4 mEq of potassium and 3.0 mmol per L or 93 mg of phosphate).	C	14