Consequences Of Vitamin Toxicity

Vitamin toxicity is common for those who overconsume a certain food or take too much of a particular vitamin. Although all vitamins are vital to many functions in your body, too much of any type of vitamin can cause health problems and can even lead to death. If you think you have a vitamin deficiency in your diet, consult with a physician or registered dietitian to determine how much you really need and what type of diet to adopt to attain optimal vitamin levels.

Hypervitaminosis A

The upper-limit intake of vitamin for adults (age 19 and over) is 3,000mcg a day. Too much Vitamin A (particularly retinoids) causes hypervitaminosis A, in which the symptoms are liver failure, reduced bone density, hair loss, excessive skin dryness, blurred vision, nausea and vomiting. Many vitamin supplements sold in stores often have 200 percent or higher doses of Vitamin A, which is a common cause of hypervitaminosis A. Another common cause of toxicity is eating too many animal livers, which contain a high amount of Vitamin A.

Hypercalcemia

Vitamin D's primary function is to maintain normal blood calcium concentrations. If too much Vitamin D is taken, it causes abnormally high blood calcium concentrations, which leads to overcalcification of bones and soft tissues, kidney stone formation and hypertension. Symptoms of hypercalcemia include dehydration, vomiting, reduce appetite, constipation and chronic fatigue. Avoid hypercalcemia by not taking more than 400mcg of Vitamin D a day.

B Vitamins

Unlike fat-soluble vitamins, like Vitamin A and Vitamin D, B vitamins are water-soluble, which are easily excreted in the body and do not store in the body easily. However, they, too, can build up to toxic levels if too much are consumed. Some B vitamins do not have any known toxicity in large amounts, such as riboflavin (Vitamin B2), Vitamin B12 and folate (Vitamin B9), although folate is known to mask symptoms of Vitamin B12 deficiency.

Too much of thiamine (Vitamin B1) causes too much muscle relaxation and drowsiness, which can inhibit sports performance and focus.

Niacin (Vitamin B3) in large quantities causes liver damage, elevated blood sugar, itchy, dry skin and cardiac arrhythmia.

Too much Vitamin B6 causes nerve damage and reduced body awareness (proprioception) which deadens the nerves, causing falls, poor coordination and disorientation.

Many negative effects of water-soluble vitamins can be reversed when the megadoses are discontinued.