Vitamin Toxicity: How much is too much?

Many of us believe that taking abundant amounts of vitamins cannot harm us. This is true for some vitamins like C and B. When we take too much of those vitamins we just urinate the excess. However, there are 4 vitamins which are stored in fat. The vitamins stored in fat (aka fat-soluble) are A, D, E and K. All of them are components in multivitamins. When these fat-soluble vitamins are taken in excess, there may be serious consequences.
Vitamin D is being used by many in the ageing population to prevent or to treat osteoporosis. We can find vitamin D in milk, orange juice, multivitamins and most calcium tablets. It is also found in prescription medications like Fosamax-D. Our bodies also produce it when we are exposed to sunlight. The recommended daily allowance (RDA) is 1000IU. When a person takes in more than this on a daily basis they are at risk for high blood pressure, nausea, vomiting and lack of appetite.
Vitamin A is found in multivitamins, spinach, carrots, leafy vegetables, pumpkin and pretty much any fruit or vegetable with an orange tint. It is used to preserve our vision, immune and reproductive systems. It is also found in prescription medications used for acne as isotretinoin. The RDA is 5000IU. Overdose causes hair loss, dry skin, nasal irritation, fever, insomnia, fatigue, weight loss, anemia and diarrhea.
Vitamin E is used to boost the immune system, as an antioxidant and to protect the skin. Vitamin E can be obtained from asparagus, avocado, eggs, milk, nuts, spinach, vegetable oil and whole grain foods. The RDA is 30IU. It is also supplied in multivitamins.
Vitamin K helps our bodies clot blood and is used to reverse Warfarin overdose. Sources of vitamin K include green, leafy vegetables, cauliflower, brussel sprouts and cabbage. Just like the others, it is found in multivitamins. The RDA is 75mcg. This vitamin and its amount is important in patients taking Coumadin or warfarin. Overdose can cause our clotting system to go haywire.
The majority of the effects listed were of a milder form. The take home point is to attempt to regulate how much of these vitamins you consume on a daily basis and to recognize the signs and symptoms of overdose.