Overdose Of Vitamins

Scientists divide vitamins, the organic compounds essential to life, into two groups; water-soluble vitamins and fat-soluble vitamins. The water-soluble vitamins, which include the B vitamins and vitamin C, dissolve in and get absorbed with water, while fat-soluble vitamins get absorbed by binding to fatty acids. The body flushes out excess amounts of water-soluble vitamins, making an overdose unlikely. Fat soluble-vitamins, however, including vitamins A, D, E and K, get stored in the fat cells and the liver, so taking too much can lead to an overdose with symptoms of toxicity.

Vitamin A Overdose

Food sources of vitamin A contain carotenoids, also known as pre-vitamin A, that the body converts into vitamin A. Vitamin A supplements contain preformed vitamin A, or retinol, in the form of retinyl palmitate or retinyl acetate. A vitamin A overdose, medically known as hypervitaminosis A, usually only occurs due to an overdose of preformed vitamin like that found in supplements. The body readily absorbs this type of vitamin A but slowly removes it from the body so an overdose can occur after taking a large amount in a short time period, known as an acute overdose, or taking a smaller amount for a long period of time, known as a chronic overdose. Symptoms of an acute toxicity include nausea, headache, fatigue, loss of appetite, dizziness and can cause fluid to build up in the brain, known as cerebral edema. A chronic toxicity also causes a headache, loss of appetite and cerebral edema along with joint or bone pain. To prevent an overdose the National Institute of Medicine set the tolerable upper level intake -- defined as the maximum amount likely to produce no adverse effects -- for vitamin A at 3,000 micrograms per day.

Vitamin E Overdose

Since the best food sources of vitamin E include vegetable oils like olive oil, soybean oil and corn oil, the risk for consuming too much remains low. Taking vitamin E supplements increases the risk for a vitamin E overdose. The Linus Pauling Institute reports study results that show taking 2,000 mg of vitamin E per day causes few side effects, especially if only taken for a short period of time, but the long-term side effects remain unknown. Since large doses of vitamin E can increase the risk for hemorrhage, the National Institute of Medicine sets the upper intake level at 1,000 mg per day.

Vitamin D Overdose

The body needs vitamin D in order to absorb calcium needed to build strong bones and teeth, but too much vitamin D can cause a variety of symptoms, some of which can become serious. A vitamin D overdose can lead to weight loss and anorexia. It can also raise the amount of calcium in the blood which affects the cardiovascular system including the blood vessels and the heart. Too much calcium can affect your normal heart rhythm leading to arrhythmia and heart damage. A vitamin D overdose and resulting increase in blood calcium can also cause kidney damage as the kidneys work overtime to remove the excess calcium from the blood. The National Institute of Health Office of Dietary Supplements reports the tolerable upper limit for vitamin D as 100 micrograms per day for everyone over the age of 9, which corresponds to 4,000 IU, International Units, per day.

Vitamin K Overdose

Vitamin K plays an essential role in the coagulation, or clotting, of blood. Without enough vitamin K blood cannot clot increasing the risk for bruising and bleeding. A vitamin K overdose can also cause serious medical problems. Although there are no known cases of toxicity due to consuming too much of the two most common forms of vitamin K, K1 also known as phylloquinone and K2 also called menaquinone, vitamin K3 a synthetic form of the vitamin known as menadione can cause problems. Taking too much vitamin K3 causes oxidative damage to cells and may lead to liver toxicity and jaundice especially in infants. For this reason, this form of vitamin K is used less often.