Eating a well-balanced diet is a must because vitamins and minerals are crucial supporters of your health and physical development. However, all vitamins and minerals come with an established safe range for consumption, and many come with a set maximum dosage. Exceeding this amount -- particularly by taking too much of a supplement -- may backfire and cause serious health consequences.
Water-Soluble vs. Fat-Soluble Vitamins
Vitamins are divided into two different categories: water-soluble and fat-soluble. Water-soluble vitamins flush out of your body on a regular basis and need constant replacing. Alternately, your body stores fat-soluble vitamins in the liver and fatty tissues. Because your body holds onto fat-soluble vitamins for longer quantities of time, you are at higher risk of overdosing on them than you are on water-soluble vitamins, according to the Colorado State University Extension.
High-Risk Vitamins
Vitamins A, D, E and K fall into the fat-soluble category. Your body can generally tolerate a daily dose up to 10,000 IU of preformed versions such as vitamin A acetate and palmitate, but it may tolerate higher amounts of the plant precursors alpha- and beta-carotene, according to "Good Housekeeping." Risks of consuming too much vitamin A include liver damage, nervous system damage, hair loss, increased skull pressure and growth retardation. A vitamin D dose over 4,000 IU could increase your risks of problems ranging from weight loss and irritability to growth retardation and kidney damage. Taking more than about 100 IU of vitamin E in its supplemental form could cause nausea, fatigue, excessive bleeding and digestive tract disorders. Although no upper limit has been set for vitamin K, taking excessive amounts of it could cause liver damage and breakdown of your red blood cells.
Mineral Overdose
Minerals are broken down into two categories: macrominerals and trace minerals. Your body needs larger quantities of macrominerals such as calcium, sodium, chloride, magnesium, phosphorus and potassium and smaller amounts of trace minerals such as iron, zinc, iodine and copper, according to MedlinePlus. As a result, you are at higher risk of overdosing on trace minerals. For instance, you are at higher risk of constipation and potentially cancer and heart disease if you take too much iron. You need about 18 mg of iron per day if you are a premenopausal woman and about 8 mg of it if you are a man or a postmenopausal woman. If you take too much zinc, you may have a reduced ability to absorb copper; this could weaken your immune system. Aim for no more than about 15 mg of zinc per day.
Tips
You are less likely to consume a toxic amount of vitamins and minerals if you get them from a well-balanced diet and are generally healthy otherwise. Whole foods also tend to offer other benefits that supplements can't offer: They are more complex and contain various micronutrients your body requires, they contain fiber and they have other protective substances such as antioxidants. If you believe you still need to take a vitamin or mineral supplement, your doctor would be the best person to recommend one for your specific needs. He will likely recommend that you find one that offers about 100 percent of your daily value of all vitamins and minerals and suggest avoiding "megadose" supplements. He will also recommend that you check the label to make sure you're taking the recommended serving size.
References
- "Good Housekeeping"; Can You Overdose on Vitamins and Minerals?; Janis Jibrin, M.S., R.D.
- Colorado State University Extension; Fat-Soluble Vitamins; J. Anderson and L. Young; 2008
- MedlinePlus: Minerals
- Office of Dietary Supplements: Vitamin D
- MayoClinic.com: Dietary Supplements: Nutrition in a Pill?
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