Toxicity and Overdose of Vitamin D
Vitamin D toxicity can be life threatening, as a matter-of-fact some pesticide companies manufacture fatal rodent baits made of large amounts of Vitamin D.
Vitamin D overdose is extremely rare and a vitamin D deficiency can have serious health consequences.
Signs of Vitamin D Toxicity
The initial sign of a Vitamin D overdose is high calcium in the urine. This condition is called hypercalcura.
The next sign of Vitamin D toxicity is the evidence of excess levels of calcium in the blood, called hypercalcemia.
Some of the symptoms a person may experience are; nausea, poor appetite, vomiting, bowel difficulties either (or both) diarrhea and constipation. Other signs include weight loss, excessive thirst (polydipsia) and/ or tingling in the mouth, weakness, and confusion. This condition can also cause heart irregularities.
Other symptoms may include itchy skin, over production of urine (polyuria), bone pain, kidney stones, and nervousness.
What exactly constitutes a toxic dose of vitamin D has yet to be determined, though it is possible this amount may vary with the individual, below is the chart provided by Health Canada that shows the DRI’s (Dietary Reference Intakes) and the UL’s (Tolerable Upper Intake Level).
How can you overdose on Vitamin D?
Our body’s do not excrete excess vitamin D nor does it stop absorption of large quantities. It will continue to store it to toxic levels.
High levels of vitamin D are caused by misuse of, and excess amounts of supplements; usually ingested over a period of time.
People at risk of vitamin D toxicity
Vitamin D toxicity is rare even in people who take prescribed supplements but there are some drug interactions that can cause complications with high amounts of vitamin D.
Drug interactions Vitamin D
If you are considering supplementing your diet with additional vitamin D you should always check with your medical practioner especially if you are taking or have any of the following:
Thiazide-type diuretics, preexisting conditions of the kidney and liver, Corticosteroid medications like prednisone, Orlistat – a weight loss drug (brand names alliTM and Xenical®), phenytoin and phenobarbital (Dilantin®), as well as cholestyramine (brand names Prevalite®, LoCholest®, and Questran®).
Other persons who may be at risk are ones who have been taking prescribed, high doses of vitamin D for a medical condition like Rickets. Over a long period of time vitamin D could reach toxic levels.
Food and vitamin D toxicity
There are a few foods – like salmon – with high levels of vitamin D, but it isn’t in enough quantities to cause an overdose of vitamin D. In this case Cod Liver Oil is considered a supplement and not a food source.
Sunshine and vitamin D
Vitamin D is known as the sunshine vitamin and is our primary source. Sun exposure cannot cause vitamin D toxicity. The skin produced vitamin D is made possible my ultraviolet B (UVB) ray exposure. Either natural sunlight or tanning beds. If you do use a tanning bed for vitamin D production, check to ensure they do not use the UVB blocking glass.
Because vitamin D production in the skin is a natural occurrence, once we have produced enough for the day, it stops production usually after 30 minutes of full body skin exposure to the sun. A person (depending on skin tone) makes about 10,000 IU of vitamin D within those 30 minutes.
Treatment of vitamin D toxicity
If you suspect vitamin D overdose check with a medical practitioner. Some of the treatments they may recommend may be; directing you to stop taking vitamin D supplements, reducing calcium consumption, prescribing alternate medication, increased water intake, and you may also need hospitalization.