Hypervitaminosis D
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [3]; Associate Editor(s)-in-Chief:
Hypervitaminosis D is a state of Vitamin D toxicity.
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Overview
Overdose occurs at more than 100 times the recommended daily allowance (roughly one bottle of vitamin D tablets per day), over a period of months. Acute overdose requires over 50mg (ten thousand times the RDA). Foods contain low levels, and have not been known to cause overdose. Overdose has occurred due to industrial accidents, for example when incorrectly formulated pills were sold or missing industrial concentrate cans misused as cans of milk.
Symptoms and presentation
Symptoms of vitamin D poisoning include:
- Dehydration
- Vomiting
- Decreased appetite (anorexia)
- Irritability
- Constipation
- Fatigue
An excess of vitamin D causes abnormally high blood concentrations of calcium (hypercalcemia) which can eventually cause severe damage to the bones, soft tissues, and kidneys. It can also damage the kidney and produce kidney stones. Ongoing research indicates antagonism with oil soluble menatetrenone, MK-4, an internally transported natural form of vitamin K2, which is associated with bone formation and calcium retention in the bones.
Note: Hypervitaminosis D symptoms appear several months after excessive doses of vitamin D are administered. In almost every case, a low calcium diet combined with corticosteroid drugs will allow for a full recovery within a month.
Contraindicated medications
Vitamin D toxicity is considered an absolute contraindication to the use of the following medications:
Comparative safety statistics
Deaths by vitamin poisoning appear to be quite rare in the US, typically none in a given year. However before 1998, several deaths per year were typically associated with pharmaceutical iron-containing supplements, especially brightly-colored, sugar-coated, high-potency iron supplements, and most deaths were children[1]. Unit packaging restrictions on supplements with more than 30 mg iron have since reduced deaths to 0 or 1 per year[2]. These statistics compare with 59 deaths due to aspirin poisoning in [3], 147 deaths associated with acetaminophen-containing products in [4], and an average of 54 deaths per year due to lightning for [5].