Prescription vitamin D differs from over-the-counter vitamin D in that prescription vitamin D is used for many conditions and not just as a dietary supplement. Prescription vitamin D is available in various forms and different formulations. Depending on the form and formulation, prescription vitamin D is used for recurring rickets, low phosphate level, hypoparathyroidism, psoriasis, low calcium level in dialysis patients and patients with hypoparathyroidism, secondary hyperparathyroidism and hypoparathyroidism in patients with chronic renal failure. These forms of vitamin D may produce side effects.
Skin reactions are common with vitamin D cream. Ten percent of individuals using the calcipotriene cream for psoriasis experienced burning, itchiness, skin rash, irritation, stinging and tingling on the site of application during the clinical trials. About 5 percent of individuals developed dry skin, peeling, skin lesions and a worsening of psoriasis. Itchiness and skin lesions may also be seen with doxercalciferol and the topical form of calcitriol. These side effects should improve over time; however, if you develop a rash that spreads or worsens, call your physician right away.
Nausea and Vomiting
Doxercalciferol and paricalcitol may produce nausea and vomiting. About 21 percent of patients on doxercalciferol may experience these side effects. Loss of appetite and stomach pain may also occur. Nausea may occur in up to 13 percent of patients on paricalcitol and vomiting in up to 8 percent. Gastrointestinal bleeding may be seen in about 5 percent of individuals on paricalcitol, as well. Calcitriol may produce stomach pain, loss of appetite, dry mouth, metallic taste in the mouth and nausea. These side effects may diminish over time, but if any of these worsen, seek medical care right away.
Edema, which is swelling due to the accumulation of fluid, may occur with the use of doxercalciferol and paricalcitol. It is seen more commonly with doxercalciferol, occurring in about 24 percent of individuals, while about 7 percent of patients may experience edema with paricalcitol. If you experience edema, speak with your physician.
Headache and Discomfort
Doxercalciferol may cause headaches in up to 28 percent of individuals. Ergocalciferol, calcitriol and paricalcitol may produce headaches, as well. A general feeling of discomfort or weakness may occur in about 28 percent of individuals on doxercalciferol. Patients on paricalcitol and calcitriol may experience bone and muscle pain, dizziness and lightheadedness.
High Calcium and Phosphate
A rise in the levels of calcium and phosphate may be seen with vitamin D therapy. This vitamin facilitates absorption of calcium through the intestines. Your physician should measure these levels regularly through a blood test. If levels are high, your physician can adjust the dose or discontinue the drug.