Vitamin D2 Dangers

Vitamin D2 is a type of vitamin D supplement that’s also called ergocalciferol. Your body needs vitamin D mainly to support bone health. Although vitamin D is an essential nutrient, some people shouldn’t take vitamin D2 supplements, and ergocalciferol may pose toxicity risks and cause negative interactions with certain medications. Before you begin taking vitamin D2 or any other form of vitamin D supplement, talk with your doctor to discuss both the possible benefits and the possible dangers.


Vitamin D is both an essential vitamin and a hormone that your body uses to properly absorb calcium. You can get vitamin D from skin exposure to sunlight. Vitamin D2 is the form of vitamin D that’s most commonly used in supplements and added to milk or fortified foods. These supplements are used to help correct deficiencies as well as to prevent and treat osteoporosis. Vitamin D2 may also help in preventing cancer, diabetes and hypertension, as well as in treating seasonal affective disorder, polycystic ovary syndrome and psoriasis. Additionally, ergocalciferol supplements are sometimes recommended for helping to treat hypoparathyroidism, rickets and low blood-phosphate levels.


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One of the major risks of vitamin D2 is toxicity. Vitamin D2 can accumulate in your body, causing toxicity symptoms and dangerously high blood levels of calcium. You can even die from vitamin D2 doses that are five times higher or more than the recommended daily intake.

The safest maximum dosages of vitamin D2 are 4,000 international units or “IU” in most adults and children older than nine years of age. During pregnancy or while breastfeeding, you should limit your daily intake of vitamin D to 400 IU or less. Toxicity or overdose symptoms associated with vitamin D2 include headaches, dry mouth, nausea and vomiting, constipation, drowsiness, weakness, muscle and bone pain, heart-rate changes, confusion, fainting and a metallic taste in your mouth.


Vitamin D2 can also pose dangers to people who have certain medical conditions, such as those with malabsorption syndromes, hypervitaminosis and hypercalcemia. If you have hyperparathyroidism or sarcoidosis, you must talk with your healthcare provider before taking ergocacliferol or any other form of vitamin D.

Drug Interactions

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If you take calcium-channel blockers, taking vitamin D2 supplements could inhibit the medications’ effects. Ergocalciferol can also interact negatively with thiazide diuretics, leading to excessive calcium levels in your blood. Mineral oil, which is sometimes taken as a laxative, can interfere with your absorption of vitamin D2. Adverse interactions can also occur with taking vitamin D2 while taking steroids like prednisone, sucralfate or Carafate, and digoxin or digitalis.