Taking large amounts of vitamin supplements is sometimes confused with well-being and health. Combinations can result in excessive doses. Eating foods fortified with extra vitamins, drinking vitamin infused waters, consuming sports drinks, and eating meal replacements with vitamins gives an over load of vitamins. Add taking multi-dose pack vitamins along with an extra single vitamin pill or supplement, and the risk for vitamin excess increases.
Vitamin A Overdose and Symptoms
Vitamin A, a fat-soluble vitamin, can cause nausea, headache, and blurred vision in excessive doses. Too much vitamin A can lead to bone loss. Studies have shown a possible increase in hip fracture risk. Varying results from two studies (reported by the Harvard School of Public Health ,The American Thoracic Society), show an increase in lung cancer in smokers or an increase in bladder or thyroid cancer.
Vitamin B Overdose and Symptoms, Thiamin, Niacin, B6 and B12
Thiamin or vitamin B1 overdose can cause muscle lethargy and tiredness. Niacin (B3), even in normal doses, may cause facial flushing in some people. Overdoses will eventually create liver toxicity but first cause nausea and vomiting. Higher doses can cause heart irregularities and acidosis. This drug does not disguise or help “flush” illicit drugs, as is sometimes believed, so there is no need to take niacin before urine drug screens, a common cause of overdose.
Vitamin B6 may help mood and PMS but too much causes nerve damage. Taking folate, another B vitamin, may mask a B12 deficiency. B12 deficiency is found in people with reduced gastric acid or who have had gastric surgeries or bisections. B12 doesn’t need to be injected, but if taking oral pills and deficient, take 1000mg/day. Otherwise a multivitamin with B12 may be enough. Diet programs including B12 usually only offer minuscule amounts. B12 has no known toxicity but can cause some eye problems with enormous amounts ingested. It is water-soluble.
Vitamin C Overdose Causes Stomach Problems
Water-soluble vitamins are flushed out when large doses are taken but can still do harm when taken in excess of needed amounts. Large doses of vitamin C (greater than 2000mg/day) can cause gastric upset such as nausea and vomiting and diarrhea. Kidney stones are a risk of excessive vitamin C doses in those who have previously experienced kidney stones.
Vitamin D Toxicity
Vitamin D is the new wonder vitamin. But how much is a healthy amount? The average person needs 1000-2000 IU/d to have a blood level of 30 ng/ml. Levels are normal up to 100ng/ml. Toxic levels over 150-ng/ml result in hypocalcaemia and hyperphosphatemia. There can be nausea and vomiting and changed mental status. This level can be reached in one month if an infant receives 40,000 IU a day or in several months by giving adults similar dosages. Evaluate supplements called " bone health " or similar calcium multi-dose pills to check the amount ingested of this vitamin. Add that amount to a single calcium pill and a regular multi-vitamin for a total amount ingested. If additional single 2000 IU doses of vitamin D3 are taken, then large amounts might be consumed. Vitamin D2 can also provide sources of vitamin D, although D3 is preferable, so there is no need to combine the two and take even more.
Vitamin E Excess Doesn’t Help Prostate
Where it was once believed vitamin E might reduce prostate cancer, it is now believed men taking vitamin E may have a slight increased risk. Vitamin E from food is healthful, but there are conflicting opinions on supplementing with vitamin E. Caution is advised by the Mayo Clinic website as well as from results of a study by Johns Hopkins University against mega doses of this vitamin.
Vitamin K Affects Blood Clotting
Vitamin K in high doses can affect the clotting factor for those on blood thinning medication or even daily ASPIRIN®. People on warfarin or Coumadin need a consistent diet, so adding or subtracting vitamin K can cause problems. Normally vitamin K is not needed as a supplement and is provided in some green vegetables like broccoli, Brussels sprouts and lettuce, among others.
Vitamins are marketed for many purposes and cures. Usually most vitamin needs can be satisfied with proper diet. Some vitamins need supplementation such as vitamin D. Read all labels carefully and use caution especially if taking multiple doses of combination vitamins.
Further Reading on the Effects of Vitamins
Weight Loss and B6, A Vitamin for Diet, PMS, Depression and CTS
Supplements for the Mind Body Problem, Inflammation and Stress
References:
JAMA, 2009,301(1)
Prescribers Letter, Vitamin D Dosing: An Update,July 2010
Prescriber's Letter; January 2009; Vol: 16
MMWR, Use of Niacin in Attempts to Defeat Urine Drug Testing April 20, 2007 / 56(15)
Amy Andersen - Amy Andersen, MSN, ARNP, family & pediatrics certified, practices yoga and explores the inter-relationships of mind body fitness and ...
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