How Many Vitamins Are Too Many?

Vitamins and other nutritional supplements have gained popularity in recent years with the trend toward natural health and alternative medicine. While the addition of certain supplements is beneficial, they can also be harmful if taken in large quantities. The following is a guide to a few supplements that should be taken with caution.

Calcium

• Calcium is an important mineral for healthy bones and teeth. Calcium deficiency is the leading cause of osteoporosis. Consult a physician for individual dosages. Toxicity can occur at as low as 2 to 3 grams per day. Signs of an overdose include: confusion, irregular heartbeat, pain, nausea and vomiting. Large quantities of calcium supplements may even cause heart damage.

Vitamin E

• Vitamin E, or tocopherol, is a powerful antioxidant. It protects the cells from free radical damage. It is found in many fruits and vegetables and natural oils such as wheat germ, corn oil, nuts and seeds. However, excessive amounts of Vitamin E can cause nausea, headaches, fainting and even a tendency to bleed. Large quantities also increase the risk of blood clots. The recommended dose is 8 to 10 mg or 12 to 15 international units (I.U.) per day.

Vitamin K

• Vitamin K is essential for normal blood clotting. It is found mostly in dark-green leafy vegetables. However, an overdose of Vitamin K can cause liver damage and even brain damage in infants. While it is unlikely that overdose will occur from eating vegetables, it is easy to overdose with supplemental Vitamin K. For this reason, it is only available by prescription. If your doctor has prescribed Vitamin K, take only as directed.

Vitamin C

• Vitamin C is a water soluble vitamin that has a variety of essential functions in the body. It is necessary for tissue repair and in the manufacturing of collagen. It is used in the metabolism of several amino acids, minerals and other vitamins such as folic acid. It supports the immune system and nervous system, and is required for the absorption of proteins. It is readily available in many fruits and vegetables, though supplemental Vitamin C is recommended for nutritional support. Anywhere from 500 to 2,000 mg can be taken throughout the day with water. However, large quantities can cause bleeding, headaches, flushed face, nausea, vomiting and diarrhea.

Vitamin B-3

• Vitamin B-3 is also known as niacin. It is essential in the production of enzymes. It also helps to dilate the blood vessels and decrease blood cholesterol. It occurs naturally in beef liver, chicken and dried beans. Excessive quantities of niacin will cause what is known as a "niacin flush." The body will become red and hot, and fainting can occur. It is important not to exceed the recommended daily dose: 14 mg for women and 16 mg for men.

Vitamin B-6

• Vitamin B-6, or pyridoxine, is essential to metabolism. Many take supplemental Vitamin B-6 to lose weight. However, it should be used with caution. The B vitamins work in conjunction with each other. Taking large amounts of one of these may cause an imbalance with the others. Excessive amounts of B-6 can cause nerve damage, and prolonged use may cause dependency. Follow the recommended dose of 1.5 mg per day.

Vitamin B-12

• Vitamin B-12 is important for proper metabolism of carbohydrates and proteins, and is also commonly taken for weight loss. Again, it should be taken in conjunction with other B vitamins (B complex) to avoid deficiency. Very large quantities of B-12 can cause skin itching and diarrhea. But, when taken along with Vitamin C, it can lead to nose bleeds or ear bleeding. With all water soluble vitamins, it is best taken in small amounts throughout the day, with plenty of water.