Hyperlipidemia (eg, potential exacerbation of LDL elevation). Risk of metastatic calcification due to hyperphosphatemia. Potential exacerbation of hypercalcemic effects in arteriosclerosis, cardiac conditions & renal impairment during use. Patients w/ renal osteodystrophy/other conditions requiring high doses of pure vit D; sarcoidosis/other granulomatous disease. Enhanced risk of hypercalcemia in concurrent use w/ Ca-containing prep, other vit D-containing prep or vit D analogs, or thiazide diuretics. Liver disease & hepatic insufficiency. Renal insufficiency. Pregnancy & lactation.