Vitamin C Deficiency and Overdose
You Don't Have to Be a Sailor on a Pirate Ship to Suffer Vitamin C Deficiency
The form of vitamin C deficiency known as scurvy was once the scourge of sailors on the seven seas. Especially deadly on poorly provisioned ships manned by sailors kidnapped into service, lack of fruits and vegetables providing vitamin C caused the appearance of sores, loose teeth, dementia, and even death in as little as 90 days. Even young sailors in their teens and 20's died from the disease.
In the late eighteenth century, however, the British navy discovered that limes and other citrus fruit, which are rich in vitamin C, prevented scurvy. That is how British sailors came to be known as "limeys." Preventing the scourge of scurvy helped make the British navy invincible for nearly 100 years.
Even though it takes 90 days to develop scurvy, it takes less than 90 minutes for most the vitamin C in your bloodstream to break down. In fact, it only takes about half an hour for half of the vitamin C in circulation to be used up.
Our bodies have to have a constant supply of vitamin C from food and supplements. And because the supply of vitamin C vanishes so quickly, even in the twenty-first century, there are people who get scurvy.
Who Comes Down with Vitamin C Deficiency?
Some people just don't eat their fruit and vegetables, either because they don't like them, or because they absolutely cannot afford them. In most developed countries, including places like the USA, UK, Turkey, Saudi Arabia, and Japan, the people most prone to lack of vitamin C are:
- The elderly in nursing homes,
- People who can eat solid food but who have trouble with fiber and do not eat vegetables, such as people with irritable bowel syndrome or colostomies, and
- Children and infants on an all-milk diet.
Many young parents do not realize that babies cannot be fed exclusively on cow's milk. Cow's milk does not contain vitamin C in any appreciable amount. When babies or older children do not get other sources of vitamin C, their symptoms can include:
- Failure to grow teeth or premature loss of baby teeth,
- Difficulty walking because the joints are not fully formed,
- Bruising that isn't explained by injury,
- Pain while walking, and
- Sores on the skin and in the mouth.
Adults who are deficient in vitamin C can develop similar symptoms. Fortunately, it's very easy to correct a lack of vitamin C and the effects are dramatic.
How Do You Treat Vitamin C Deficiency?
A baby who is deficient in vitamin C begins to perk up after getting just 100 mg a day for several days and then changing the diet so fruit is eaten every day. Older children may benefit from taking 250 mg twice a day for 2 or 3 days and then dropping back to 100 mg a day, with a glass of juice every day. Adults usually need 500 mg twice a day for 2 or 3 days followed by 100 mg a day for 2 or 3 months. It's very hard to get these levels of vitamin C without eating a lot of fruit, so vitamin C supplements work best.
The results are usually dramatic. The gums stop bleeding in 24 hours. They usually heal in just 2 or 3 days. Bone and muscle pain usually go away in just 2 or 3 days. Any problem with walking or carrying heavy loads may resolve in a few weeks as the joints heal.
If these dosages seem low to you, remember that treating vitamin C deficiency is a matter of getting vitamin C into tissues and the tissues can only hold about 350 mg total. High-dose vitamin C works not by correcting vitamin C deficiency, but by changing the way other antioxidants work.
There is no reason for anyone to suffer scurvy. Just take vitamin C every day and you need never fear this once-dread disease.
Can You Overdose on Vitamin C?
Vitamin C is the best known and most commonly taken of all nutritional supplements. People take it because they know it works for colds, flu, and common infections, and because there is good scientific evidence that vitamin C will also help support recovery to good health in people who have high blood pressure, high cholesterol, type 2 diabetes, and cancer risk factors.
But it's always possible to get too much of a good thing. Even with vitamin C, it's possible to overdose.
Too Many Vitamin C Pills for Good Nutrition
The most common drawback to taking too much vitamin C is not to be found on some long list of vitamin C side effects. The most common problem with vitamin C overdose is just that your body cannot use it.
Humans, unless most animals, can't make vitamin C or store it in appreciable quantities. At any given time, the tissues in the human body only hold about 350 to 400 mg of vitamin C. The bloodstream can carry 100 to 200 mg more, but this vitamin C is used or breaks down very quickly. About half the vitamin C your body absorbs from food or supplements disappears from circulation in just 30 to 90 minutes. Even if you take a large dose of vitamin C first thing in the morning, your body will have used or cleared it by noon.
There are actually are specialized situations in which your body benefits from more vitamin C than it can transport into cells. If you are just taking vitamin C for good general health, however, about 500 mg a day is really all your body can use, and that should be taken in at least two separate doses. There are circumstances in which vitamin C must be taken in limited amounts, not due to the vitamin itself, but because of the way it affects heavy-metal absorption.
Vitamin C and Heavy Metal Absorption
Where high doses of vitamin C cause actual toxicity is not the vitamin itself, but the heavy metals to which it makes the digestive tract more permeable. People who have the iron overload disease hemochromatosis, for example, need to be careful about taking vitamin C because it can cause them to absorb too much iron.
The acidic foods that contain natural vitamin C also can dissolve lead. Orange juice in a pitcher glazed with lead, for example, can leach lead into the beverage and cause serious toxicity in just a few days. In these cases, however, the problem is not the vitamin C itself, it is the iron or lead that it helps the body absorb.
Vitamin C and Metabolic Acidity
Too much vitamin C may also acidify the urine. Vitamin C will never cause the whole body to become acidic. Neither will eating too much meat or cheese, for that matter. The kidneys keep excess acidity out of the bloodstream by taking calcium and glutamine from food or from bones.
The problem with acidification is that the kidneys have to take the calcium and glutamine they need to neutralize the acid from somewhere. Too much vitamin, that is, doses of 10,000 mg a day or more, along with too much meat and cheese and other acidifying foods, can put a stress on the body.
How Much Vitamin C Is Too Much?
Unless you have a very specific reason for taking vitamin C for a specific medical condition being treated by a doctor, you should not take more than 2,000 mg of vitamin C by mouth in any one day. You should not take more than 1,000 mg of vitamin C by day by mouth for more than a week. As little as 100 mg of vitamin C a day can have very positive benefits for your health. If you feel you need very high-dose vitamin C, see a qualified health practitioner about getting your vitamin C by intravenous infusion (IV).
Haffner SM. Relationship of metabolic risk factors and development of cardiovascular disease and diabetes. Obesity (Silver Spring). 2006 Jun;14 Suppl 3:121S-7S.
Johnson, Larry E. Vitamin C. Merck Manual Online, accessed 01-17-2011.