Can you Overdose on Vitamins?

Vitamin overdose
By: Dr. Obikoya

With the increasing popularity of vitamins and nutritional supplements, it is necessary to look at all sides of this phenomenon, particularly from the safety angle.

Fortified foods and supplements are in these days. They are ideal for both the busy and the health conscious. A vitamin pill or an extra muesli bar fortified with iron seems the ideal solution to compensate for a missed dinner. For dieters, it means you can limit your calories while still getting all the nutrients you need.

What’s more? These supplements a little regulated if at all. You can pick anyone of them up at your neighborhood grocery. More and more people today add nutrients to their diet by selecting foodstuffs fortified with vitamins and minerals. Manufacturers add iron to your breakfast cereals or they even add vitamin C to sweets or vitamin A to margarine. This is something that is done regularly by the food industry.

These products are intended to boost your health, but they can be anything but healthy if you overdo it. In fact, you can overdose on vitamins and other food supplements. The food industry needs to desist from advertising health benefits that are not backed up by science or putting products with mega-doses of vitamins on the market.

Vitamin C is a case in point. Swallowing some extra vitamin C to fight off a flu or cold won't really hurt, because the body only absorbs what it needs. The vitamin is normally considered harmless, even if taken in overdose but for some people this system doesn't work. Mega-doses of vitamin C may interfere with the metabolism of other important nutrients. And that, in the end, is bad for your body.

Other vitamins and minerals can be even more dangerous. Recent reports by the Food Standards Agency (FSA) found that people taking large doses of certain vitamins and minerals might permanently damage their health. FSA proposed that a balanced and varied diet gives a person all the necessary vitamins and minerals they need. So, where does that leave you?

As with most substances, it is the amount consumed that is the key. Almost anything is toxic if consumed in excess, including salt, alcohol and even water. Provided that supplements are taken in the amounts recommended on the pack by the manufacturer or retailer, and the recommended doses are not exceeded by combining too many different supplements, then it is highly unlikely that supplements will cause toxicity.

Water soluble vitamins - such as the B group vitamins and vitamin C - cannot be stored by the body to any great extent, so if you take in more than your body needs, they are simply excreted. The fat soluble vitamins A and D can accumulate in the body, but pose no danger to health if consumed within the safe upper limit indicated for them. The exception is in pregnancy, when large amounts of vitamin A may pose a risk to the developing infant.
Pregnant women should seek advice from a doctor before taking a supplement containing vitamin A and people with blood clotting disorders should seek a doctor's advice before taking supplements containing vitamin E.

Combining supplements will not normally interfere with the way they work and in some cases may be beneficial. However, certain supplements may interact with each other, for example, there is competition within the gut for the absorption of different minerals and a large dose of one might decrease the absorption of another or cause excessive absorption of another.

Therefore a multivitamin and/or mineral product is best for all-round supplementation because it delivers nutrients in the right balance. Before combining supplements, people should consult their doctor, pharmacist or the company manufacturing the supplements for advice.

As our bodies age, they become less efficient at absorbing some of the nutrients from our diet making it important to ensure that the right quantities of relevant vitamins and minerals are consumed. For example, as we get older our bodies are less able to absorb iron but Vitamin C can help increase absorption. On the other hand, we are also more prone to toxicity as even water-soluble vitamins are not excreted as much because of our less efficient kidneys. Finally, it is worth stating that quantities in excess of what we need or what is recommended may be harmful for a few individuals and that individual sensitivities and variations in response can occur, so if any unexpected symptoms appear whilst taking a particular supplement, medical advice should be sought.

If you suspect that you're taking too much of a vitamin or mineral, don't stop completely. Nutrition experts suggest cutting back to about half of your current dosage. Your body has adjusted itself to handle a massive dose, so if you stop altogether, it could trigger a deficiency. As a general rule, it's best to stay below five times the USRDA for minerals and vitamins.

If you're thinking about increasing the dosage of some nutrients or are just curious about your present vitamin regimen, consult your doctor or a registered dietitian. This is especially important if you have an illness such as diabetes or high blood pressure, since large doses of some supplements can interfere with the function of medications
Nonspecific symptoms, such as nausea, vomiting, diarrhea, and rash, are common with any acute or chronic vitamin overdose. Vitamin-caused symptoms may be secondary to those associated with additives (eg, mannitol), colorings, or binders; these symptoms usually are not severe. Each vitamin also has specific symptoms associated with its overdose. The good news is that morbidity and mortality from pure vitamins are rare. One study of acute or chronic overdoses, with more than 40,000 exposures, reported 1 death and 8 major adverse outcomes.