Drug Interaction Report

Information for this minor interaction is available on the professional version.

Treatment with cholecalciferol may require you to adjust your dietary intake of foods which contain natural or added calcium, phosphate (organic and inorganic), and vitamin D. Ingesting too much vitamin D or having elevated calcium and/or phosphorus levels in the blood and urine can lead to toxic effects, such as having an irregular heart rhythm, seizures, kidney stones, and eventual calcification of your blood vessels, cornea and/or the soft tissues in your body. Your doctor will monitor the levels of calcium and phosphorus in your blood during treatment with cholecalciferol. Please speak with your healthcare team to determine if you require a specialized diet, particularly if you have reduced kidney function, and to discuss any other questions or concerns you have. You may require additional monitoring or a dose adjustment of cholecalciferol if your diet changes. Fortified foods will state on their labeling how much calcium, phosphate, and/or vitamin D has been added. The National Institutes of Health, Office of Dietary Supplements also provides information on which foods contain calcium, phosphorus, and vitamin D. You should avoid abrupt changes in your dietary calcium intake and seek medical attention if you experience early symptoms of vitamin D intoxication such as weakness, fatigue, headache, drowsiness, vertigo, ringing in the ears, loss of appetite, nausea, vomiting, constipation, dry mouth, metallic taste, muscle pain, bone pain, muscle incoordination, and low muscle tone. Late symptoms may include frequent urination, excessive thirst, weight loss, conjunctivitis ("pink eye"), light sensitivity, runny nose, itching, increased body temperature, and irregular heart rhythm. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Both smoking and excessive caffeine consumption can alter the blood levels of melatonin, which may affect the dosing. Tobacco smoking reduces, while caffeine increases melatonin blood levels. If you start smoking or undergo smoking cessation, your doctor may need to adjust the dose of melatonin. In addition, alcohol may reduce the effect of melatonin on sleep. It is best to avoid alcohol consumption during melatonin therapy. Talk to a healthcare professional if you have any questions or concerns. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.