Vitamin Overdoses: Side Effects of Vitamin Overuse

Although taking a multivitamin can play a vital role in promoting your overall health, as with any substance, taking more than the recommended amount can cause mild to severe health problems. While some people overdose on vitamins by taking too many supplements, others may ingest excessive amounts of certain nutrients by eating nutritious foods and also taking supplements.
 
Similarly, some individuals may have unique vitamin and mineral needs that fall below the traditional nutrient recommendations set forth by the Food and Drug Administration (FDA). For example, certain chronic and/or passing health conditions can reduce the amount of particular vitamins that a person needs. In such cases, these people are at a higher risk of experiencing vitamin toxicity.

Symptoms of Vitamins Overdoses

The following are some of the most common symptoms associated with vitamin overuse:
  • diarrhea
  • general fatigue
  • hair loss
  • headaches
  • insomnia
  • joint pain
  • nausea
  • vomiting.
Overdosing on some vitamins can throw off your body’s ability to absorb and/or use other nutrients, putting you at an increased risk of suffering from both an overdose of one vitamin and a deficiency of another. In these cases, you are likely to experience more types of symptoms that are more intense in nature.
 
Because the above symptoms are fairly general, see a doctor immediately if you suspect that you are suffering from a vitamin overdose.
 
Your doctor will be able to determine whether you are suffering from vitamin toxicity or whether your symptoms are being caused by some other, more serious underlying condition. If you have, in fact, overdosed on vitamins, your doctor may prescribe you medication to minimize the symptoms until your body’s nutrient levels return to normal.

Health Complications Associated with Vitamin Toxicity

Here is a table that outlines the functions of some of the most essential nutrients, including the respective health complications that can arise when vitamin overdoses occur. The recommended daily intake for each of these nutrients is geared for healthy adults between the ages of 18 and 50.
 
Those above or below the age range, or anyone who suffers from some chronic or passing health problems, will have different nutrient requirements. If you have a question about the amounts of various nutrients that you should take, talk to your doctor.

Type of Nutrient

Role of Nutrient

Maximum Recommended

Daily Intake

Mg=Milligrams

Mcg=Micro- milligrams

IU=International Units

Complications Associated with Overdoses

Vitamin A

Vision health, clear skin, hair/teeth/bone production and maintenance

5,000 IU

Vision problems, general fatigue, liver problems, diarrhea, loss of hair, headaches, menstruation problems

Vitamin B6

Red blood cell production, metabolism, healthy blood

2 mg

Depression, general fatigue, headaches, loss of sensation in the hands and feet

Vitamin C

Immune system health, free radical cell elimination, cancer prevention, collagen production

60 mg

Headache, hot flashes, general weakness, insomnia, kidney problems

Calcium

Bone health, muscle strength, hormone production, enzyme interaction

1,000 mg

Slower nerve function, general fatigue, kidney stones

Vitamin D

Calcium absorption, bone strength, oral health

400 IU

Nausea, general weakness, high blood pressure, increased cholesterol levels, headaches, deafness

Vitamin E

Red blood cell health, metabolism, energy, skin health

30 IU

Extreme fatigue, increased blood clots, high blood pressure, slower healing

Iron

Metabolism, neuro- transmitter production, blood health

8 mg (men)

18 mg (women)

Liver damage, heart problems, pancreatic complications, constipation

Niacin

Digestive system health, nerve system health, skin health, energy

16 mg (men)

14 mg (women)

Liver problems, gout, general fatigue, irregular heartbeats, high blood sugar

Selenium

Thyroid health, proper hormone production and functioning

150 mcg

Weakness, nausea, loss of nails on fingers and toes

Zinc

Immune system health, proper enzyme activity, normal physical development, healing from injury

11 mg (men)

8 mg (women)

Hand tremors, loss of muscle control, slurry speech

Resources

Rogers, J.R. (n.d.). Vitamins: What They Do For You. Retrieved November 12, 2007, from the Bodies of Stone Web site: http://www.bodiesofstone.homestead.com/
VitaminFunctions.html.  
 
Vitamins to Health (n.d.). Vitamin Overdose Symptoms. Retrieved November 12, 2007, from the Vitamins to Health Web site: http://www.vitaminstohealth.com/vitamin-overdose.html.
Share |