Diet News Science

Vitamin Toxicity

Ever wondered which vitamins can cause toxicity and how? Here below you will find some useful information about the side effects relating to the over-consumption of some very popular supplements:

Fat-soluble vitamins:

  • VITAMIN D: Taking Vitamin D in high dosages can cause troublesome side effects that include nausea, joint pain, vomiting, loss of appetite and constipation. Other symptoms associated with overdose are tingling in the mouth, lung damage and heart & kidney complications.
  • VITAMIN A: Vitamin A overdose can result in a variety of symptoms, such as vomiting, constipation, bone pain, headaches and even Hydrocephalus. Other potential effects include dry skin, hair loss and brittle nails. It is important to be aware of these possible side effects when consuming any vitamin supplements.
  • VITAMIN K: An excessive intake of Vitamin K often leads to anemia, which then reduces the levels of blood cells in the bloodstream.
  • VITAMIN E: Taking an excessive amount of Vitamin E can lead to some issues such as headaches, double vision, diarrhea and stomach ache. Therefore, it is important to check the dosage instructions before consuming Vitamin E.

Water-soluble vitamins:

  • VITAMIN B12: Vitamin B12 has a history of being very safe to consume, with no reports of toxicity in pernicious anemia patients. However, when vitamin B12 is administered along with folic acid for certain anaemias, it can cause some complications. Folic acid therapy can help to prevent anemia from developing, but unfortunately, it does not protect against any potential nerve damage that might occur.
  • VITAMIN B 6 : Taking too much Vitamin B 6 can lead to a whole host of issues such as mobility problems, tingling feelings in the legs and bottom of your feet, having difficulties grasping items, as well as numbness in the hands.
  • VITAMIN C: People who have a familial history of developing kidney or gallbladder stones might experience the symptoms of vitamin C deficiency.

How can Genetic Testing help to control vitamin toxicity?

Genetic testing can be beneficial for people who are considering certain medications. It can help identify potential adverse reactions or side effects of the drugs, so that individuals can be better prepared for any outcome. In this way, it offers a precise way to ensure optimal health outcomes. Genetic testing can be conducted to diagnose or rule out a genetic condition for an individual. It gives doctors enough data to make the best decisions as far as prescribing medications, dosage, etc., is concerned. Ultimately, it offers a way better understanding of what would be optimal for any given patient.


Immediate cessation of consuming vitamin supplements is key to treating the issue of vitamin toxicity. Vitamin D, in particular, has a tendency to raise calcium levels in the bloodstream which can result in higher plasma calcium levels. In order to reduce plasma calcium, the consumption of vitamin D should be discontinued. For severe hyperkalemia cases, 0.9% sodium chloride solution can be administered intravenously to provide relief.


You can lower the chance of vitamin toxicity by not taking an excessive amount of vitamin supplements. If your doctor has prescribed you with Vitamin D, then it is important to keep an eye on your calcium levels in order to prevent any potential risks.

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