How Much Is A Megadose Of Vitamin D?

Megadosing on vitamin D can cause toxicity in your body. A megadose of any vitamin is 10 times the recommended level, according to information from Georgia C. Lauritzen, a food and nutrition specialist from the Utah State University Cooperative Extension. Frequently called the sunshine vitamin, because your body makes vitamin D when you expose your skin to the sun, vitamin D helps you absorb calcium to build strong bones and teeth. To prevent adverse reactions to vitamin D supplements, talk to your doctor before taking them.

Fat-Soluble Vitamins

Vitamin D, A, E and K are fat-soluble vitamins. This means your body does not need them every day, because you store extra amounts in your liver and fatty tissues. Because your body stores fat soluble vitamins, you have a greater risk of building up toxic levels in your body than with water soluble vitamins, which your body eliminates more quickly. Taking dietary supplements or eating fortified foods containing megadoses of fat-soluble vitamins, like vitamin D, may lead to toxicity according to the Colorado State University Extension Service.

Megadose

The amount of a megadose of vitamin D depends on your age and the recommended dietary allowance for vitamin D from the Office of Dietary Supplements. For children up to 12 months the recommended dietary allowance is 400 IU, making 4,000 IU the megadose for this age group. For people between one and 70 years old, even pregnant and lactating women, the recommended dietary allowance is 600 IU, making the megadose for this age group 6,000 IU. The ODS recommends people over 70 take 800 IU of vitamin D per day, making a megadose for this age group 8,000 IU.

Tolerable Upper Limit

Rather than megadosing on vitamin D, consult with your doctor about taking an amount not exceeding the tolerable upper limit instead. The tolerable upper limit for vitamin D varies with age. According to information from Medline Plus the safe upper limit for vitamin D is 1,000 to 1,500 IU per day for infants, 2,500 to 3,000 IU per day for children between the ages of one and eight and 4,000 IU per day for people 9 and older including pregnant and lactating women.

Symptoms and Increased Risk

You are unlikely to get too much vitamin D from food or the sun, but taking supplements can lead to this rare condition. Signs of vitamin D poisoning include excessive blood levels of calcium, slowed mental development, slowed physical growth and decreased appetite, as well as nausea and vomiting, according to information from the Colorado State University Cooperative Extension. If you have liver or kidney problems you are more likely to develop vitamin D toxicity than the general population, warns Katherine Zeratsky, a nutritionist from the Mayo Clinic.