Scurvy is a disease you learn about in history books, not on the evening news.
We’ve all heard the tale of 18th century English sailors who had no fruits and vegetables on long voyages. Starved for vitamin C, their bodies began to break down, until eventually they died out on the open sea. The problem ended when ships began stocking limes and other fresh fruit for the sailors to eat, earning them the nickname “Limey” ever since.
Here in modern America, people have access to a variety of fresh fruits and vegetables all year long. In the lineup of nutritional problems, we pay attention to osteoporosis and iron-deficiency anemia. Nobody worries about scurvy.
Maybe we should.
Nutrition researcher Carol Johnston measured blood levels of vitamin C among Phoenix area Cigna HMO members. The Arizona State University scientist found that six percent of her subjects were vitamin C deficient. In other words, one in 16 people showed the biochemical signs of scurvy (a physical exam is required to actually diagnose the disease).
An additional 30 percent of the sample was vitamin C depleted, meaning that they did not meet the U.S. Recommended Daily Allowance (RDA) for the nutrient.
“There’s no public health concern at all about vitamin C.” says Johnston. “I did a Medline search just to look at the cases of vitamin C deficiency reported in the medical literature. It was more than you see with iron deficiency, more than vitamin B12 deficiency—these nutrients that we accept as a problem. Vitamin C deficiency is even more pronounced and doctors are not addressing it.”
Even worse, patients who visit their doctors with symptoms of scurvy are likely to be misdiagnosed.
“If you look at case reports, people will tell their doctors that they have bruising, they’re always tired, and they have trouble walking. Doctors diagnose the problem as vasculitis or even as polio,” Johnston says. “You wouldn’t believe how many misdiagnoses appear in these case reports. Physicians are not trained to know what scurvy is, because it supposedly doesn’t happen.”
Vitamin C is involved in the production of collagen, which is used in forming gums, skin, blood vessels, ligaments, and tendons. Early symptoms of scurvy include joint pain, bruising, receding gums and loose teeth, all due to low collagen production.
Left untreated, scurvy is deadly.
“Eventually you can’t walk because your bones rub against one another. You die of cerebral hemorrhaging or massive blood loss,” explains Johnston.
Death from scurvy isn’t really a problem in the industrialized world. Even people who don’t consume the RDA for vitamin C (currently 70 milligrams for women and 95 mg for men) generally eat enough to keep them alive.
However, they probably suffer other symptoms like fatigue, bleeding gums, bruising, or frequent colds.
“Let’s say you go to the gym and get on the treadmill,” Johnston says. “You might say, ‘I just don’t feel like doing this,’ so you get off and walk away. It happens to all of us, that kind of vague, general feeling of not being well.”
That feeling might have more to do with lack of vitamins than lack of motivation. Johnston’s research has linked vitamin C depletion to low levels of muscle carnitine, a substance the body uses to produce energy from fat. She has also shown that people who receive vitamin C supplements perform better on treadmill tests than people who are vitamin C depleted.
Getting the recommended dose of vitamin C can prevent these kinds of problems. But even people who meet the RDA may be missing out on other benefits of the nutrient, according to Johnston.
Her research findings indicate that higher doses of vitamin C—about 1,000 mg per day—may offer health benefits that you can’t get from smaller amounts.
“There’s been a lot of controversy over how much vitamin C we need. The RDA is very low and still prevents scurvy. But is the prevention of disease the optimum goal? Are there other physiological functions that we’re not optimizing?” Johnston asks.
Looking around at the natural world, it would seem so. Compared with humans, other animals and plants maintain much higher blood levels of vitamin C.
“Vitamin C is unique because almost all species make their own vitamin C. Except for humans,” explains Johnston.
Even more interesting, animals that produce their own C make enough to reach blood plasma saturation levels. For humans to achieve plasma saturation, they have to eat about 1,000 mg of the vitamin each day—much more than the recommended 75-90 mg.
Primates, which are closely related to humans, do not produce their own vitamin C. However, they eat a lot more of it than people do.
“Primates might eat as much as 2 to 5 grams a day, because all they eat is foliage,” says Johnston. “Primates consume a tremendous amount of C. We evolved from primates but our diet is so different. Our dietary intake of C is very, very low.”
She adds that prehistoric humans also consumed much more vitamin C than people do today.
“Hunters and gatherers probably consumed 600 mg or more of vitamin C a day because half their diet was foliage, such as kale. Not iceberg lettuce. We’re so far removed from eating that way.”
There is one group of modern humans that routinely consumes high levels of vitamin C—breastfed babies.
“Nutritionists often look at breast milk as the perfect nutrient. Physiology has dictated how much of each nutrient appears in the milk. A breastfed baby gets a plasma saturation level of vitamin C,” Johnston says.
She believes that the high levels of vitamin C in natural systems are evidence that the nutrient is important for more than just preventing scurvy.
“Why are there so many examples of high vitamin C under natural circumstances?” she asks. “We need to figure out what function is being promoted in rats and in wild primates and in breastfed babies to dictate maintaining a blood level that high.”
Much of Johnston’s research focuses on just that. She studies the functions that vitamin C promotes, and what levels are needed to do these jobs.
During the past several years in three separate studies, Johnston has shown that high doses of vitamin C lower blood histamine levels. Histamine is the substance that causes allergy symptoms, bringing on the congestion, sneezing, and itching that plague sufferers.
“When your body is stressed, histamine levels go up. And the reason histamine goes up is because it makes you more alert, ready to fight,” Johnston explains.
“But in our society we’re under chronic stress. We have chronically elevated histamine. It’s not doing us any good because we don’t need this fight or flight process going. Your body gets all revved up and the histamine goes up. But it suppresses your immune system,” she adds.
Johnston’s research shows that people who consume 2,000 mg of vitamin C per day have a blood histamine level 40 percent lower than those who consume the RDA.
“People take antihistamines like they’re candy,” Johnston says. “Maybe the problem is we’re not eating right. Maybe if we all ate more fruits and vegetables and took vitamin C we wouldn’t have to be taking all these antihistamines.”
She is quick to add that she’s not opposed to antihistamines.
“When I have a lot of congestion I take an antihistamine, because it’s a quick relief,” she says. “Vitamin C doesn’t block the histamine receptors, which is what gives you the quick relief. What it does is lower the levels of histamines in the blood.”
In other words, vitamin C might help prevent or lessen allergy symptoms over the long term. It doesn’t act as a quick treatment for existing symptoms.
Vitamin C also functions as an antioxidant. Antioxidants play a crucial role in helping prevent many serious problems, including cancer.
Antioxidants reduce the damage from various environmental stressors. Ultraviolet radiation, pollutants, even the oxygen we breathe, all create oxidants in our bodies. Oxidants are damaging molecules because they are short an electron. To achieve stability, they “steal” electrons from other molecules. When these molecules are part of human cells, the theft of an electron can do serious damage.
“If it’s a DNA molecule you get a mutation which might lead to cancer. If it’s a lipid you get arterial plaque development. If it’s in the retina you get macular degeneration,” explains Johnston.
That’s where antioxidants come in. An antioxidant is a molecule that carries an extra electron. When it meets up with an oxidant, it donates that electron.
“An oxidant will get its electron from whatever’s next to it. So if you saturate [the blood] with vitamin C, it will be more likely to take that electron from vitamin C,” explains Johnston.
Unfortunately for most Americans, vitamin C has little antioxidant effect at doses lower than 1,000 mg per day.
The natural world offers further evidence that vitamin C is an antioxidant because only land species use it.
“In the ocean, nothing makes vitamin C. There’s no vitamin C in ocean water. Why on land but not in the ocean?” she asks.
“The difference is the environmental stressors. All living terrestrial animals and plants require vitamin C. The theory is that the vitamin C is there to protect the land plants from the insults of oxygen in the atmosphere, and from UV radiation, which causes tremendous oxidative stress,” says Johnston.
“All this oxygen we breathe in, obviously it’s vital, but it causes tremendous damage. Maybe we need the high C to protect us from all this oxygen we’re consuming.
“In my mind, we have something that we need here,” says Johnston. “Maybe we need to rethink how we look at it, because maybe the avoidance of disease is not all we should be looking at.”—Diane Boudreau
