Side effects of vitamin D2 include increased urination, especially at night, and chest pain, according to RxList. Other side effects include unexpected weight loss, weakness, fatigue and seizures, explains Healthline.
Side effects of vitamin D2 that do not require medical attention include dry mouth, constipation, headache and stomach upset, reports Healthline. Serious side effects include bone pain, seizures and allergic reactions, such as swelling of the tongue, lips and face.
Metabolic side effects of vitamin D2 include hypercalcemia, reports Drugs.com. Early symptoms of hypercalcemia include dry mouth, a metallic taste in the mouth, abdominal cramps, muscle and bone pain, and vertigo. Symptoms in later stages include mental confusion, arrhythmias and hypertension.
Vitamin D2 may interact with phosphate binders, according to WebMD. Patients should inform their doctors about taking this supplement and any other drug they are taking to prevent negative interactions. Vitamin D2 may also interact with diuretics, mineral oils and seizure medications. Individuals allergic to vitamin D, food dyes or medicine preservatives should inform their doctors before they take vitamin D2 to prevent negative side effects and allergic reactions, according to Healthline.
Vitamin D2 overdose may cause seizures, irregular heartbeat and confusion, according to WebMD. Early signs of an overdose include vomiting, weakness, nausea and a metallic taste in the mouth, reports RxList.