Vitamins & Minerals Needed By The Body In Small Amounts

Although almost all nutrients are necessary for life, the body needs each in different proportions. Particularly water-soluble nutrients that the body does not store, like vitamin C, require daily consumption of foods that contain them to maintain proper levels. Alternately, the body stores enough of some nutrients to allow longer safe durations between consumption. Others still must appear in your daily diet, but in relatively small amounts to avoid toxicity.

Toxic Trace Vitamins

Trace nutrients, or micronutrients, are those that appear in foods in relatively small amounts. Appropriately, the body requires them in similarly small amounts. In some cases, this means that you can be less attentive about your consumption of such nutrients, because meeting their required doses will likely result from regular eating. However, some micronutrients still require management, as excessive consumption could be toxic. On the other hand, such toxicity is nearly impossible when you derive these nutrients from foods. Instead, it usually occurs due to excessive supplement consumption, particularly with vitamins.

Vitamins that can be toxic when ingested in large amounts include vitamin B-9, vitamin D and vitamin K. Excess vitamin B-9, or folic acid, can cause seizures in patients taking anticonvulsants. Toxicity from the vitamin can result in symptoms suggestive of a vitamin B-12 deficiency, such as nerve damage, irritability and nerve impairment. Vitamin D poisoning results in a condition called hypervitaminosis, causing nausea and vomiting, constipation, disorientation, loss of appetite, weakness, kidney stones and heart palpitations. Vitamin K overdose can cause hemolytic anemia. Due to the unlikelihood of vitamin K overdose, there is no established upper limit for dosages. However, the upper limit is 1,000 micrograms for folate and 2,000 IU for vitamin D.

Nontoxic Trace Vitamins

Vitamin B-12 is the only nontoxic vitamin that the body requires in trace amounts. In fact, administration of vitamin B-12 in high doses is common, particularly to treat pernicious anemia, according to the Linus Pauling Institute. Accordingly, there is no established upper limit for vitamin B-12 dosages. Moreover, the body is capable of storing several years' worth of vitamin B-12.

Toxic Trace Minerals

Unlike vitamins, all trace minerals are toxic in large doses. These elements include iron, zinc, fluoride and copper. Iron is among the most toxic as the leading cause of poisoning deaths in children in the United States, according to Paul Insel and colleagues in the book "Nutrition." Accordingly, excess doses are extremely dangerous. The upper limit per day of iron is 45 mg. Although less dangerous, fluoride overdose can cause convulsions, heart attack, nausea, tremors, shortness of breath, drooling, slowed heartbeat and headaches. The upper limit for fluoride is 10 mg per day. Copper is even less toxic, causing anemia, nausea, urine cessation, jaundice, bloody diarrhea, fever, convulsions, pain, shock, liver failure, weakness, vomiting and chills. The upper limit for copper is 10 mg per day. As the least toxic mineral, zinc poisoning can cause vomiting, diarrhea, cramping, headaches and loss of appetite in high doses. Extreme cases can reduce immunologic function, lower HDL cholesterol and cause iron deficiencies. The upper limit for zinc is 40 mg per day.

It is important to note that these relative degrees of toxicity are based on severity following the onset of symptoms. Consuming any of these elements in their pure form or in industrial-grade solutions can cause death.

Considerations

Whereas trace nutrients usually are toxic in larger than normal doses, this risk does not exist when the nutrient derives from food. Not only do trace minerals appear in trace amounts, but other factors greatly reduce the likelihood that they will be absorbed into the bloodstream in toxic amounts. Examples include bioavailability, or the accessibility of these nutrients to the body, and the time it takes to extract these nutrients from food. Alternately, nutrient toxicity usually results from excessive supplement consumption. Some cases of mineral toxicity can also result from exposure to inedible material. For example, copper toxicity can result from touching too much copper wire, as the element is permeable through the skin.