Scurvy is still around — and cases are rising. Why a severe lack of vitamin C can cause the condition.

Most people are aware that eating plenty of fruits and vegetables is important for overall health. But not having enough — or any — fresh produce raises the risk of developing a serious health condition like scurvy, which indicates a severe vitamin C deficiency.

While it was once linked to 18th-century sailors living off limited diets for long sea journeys, scurvy still exists. In fact, a new case report in the Canadian Medical Association Journal details how a 65-year-old woman ended up hospitalized after mostly living on a diet of canned soup and fish, with no fresh produce.

Nearly 6% of people in the United States have a vitamin C deficiency; data also shows that scurvy cases are rising in this country. So, what is scurvy, exactly, and what are the major symptoms to look out for? Here’s what you need to know.

What is scurvy?

Scurvy is a disease caused by a severe lack of vitamin C in your diet, according to the U.S. National Library of Medicine. Vitamin C, which is also called ascorbic acid, “is essential for the synthesis of collagen, a protein that helps maintain the integrity of connective tissues like skin, blood vessels and bones,” Scott Keatley, a registered dietitian and co-owner of Keatley Medical Nutrition Therapy, tells Yahoo Life.

“Without enough vitamin C, the body can't produce or repair collagen effectively, leading to a wide range of symptoms,” he says.

Scurvy symptoms

There are a few symptoms someone might experience with scurvy. “Symptoms of scurvy usually start with fatigue, weakness and irritability,” Keatley says. “As the deficiency worsens, more serious symptoms appear, such as swollen and bleeding gums, joint pain, easy bruising, dry skin and poor wound healing.”

In severe cases, scurvy can lead to anemia and internal bleeding, Keatley says. It can even be deadly if left untreated.

Why is scurvy still around?

Scurvy is rare in the U.S., but it happens. “Historically, scurvy was described in sailors without access to fresh fruits and vegetables,” Dr. Mehruba Anwar Parris, an assistant professor of emergency medicine at Rutgers New Jersey Medical School and a medical toxicologist at New Jersey Poison Control Center, tells Yahoo Life. Now, older adults who aren’t getting proper nutrition are the most vulnerable, per the U.S. National Library of Medicine.

Scurvy mostly happens today due to poor dietary habits, Claudia Castaneda Tinoco, a registered dietitian at NewYork-Presbyterian/Columbia University Irving Medical Center, tells Yahoo Life. “Since our bodies don’t produce vitamin C, we have to get it from our diet,” she explains. “If you’re not eating enough vitamin C-rich foods, like fruits and vegetables, or if your body can’t properly absorb it, you could be at risk.”

Scurvy can also happen in people who have “extremely limited diets” due to food access issues, restrictive diets or conditions like alcoholism or eating disorders, Keatley says. “Additionally, diets lacking in diversity or heavily reliant on processed foods, which typically don't contain vitamin C, can be a factor,” he says.

Parris says that scurvy can be an issue in some communities that lack access to fresh foods. “Children and the elderly are at particular risk of the disease in these communities,” she adds.

Tinoco says gastrointestinal conditions such as inflammatory bowel disease also raise a person’s risk of scurvy.

How is scurvy treated?

Scurvy is usually treated by reintroducing sources of vitamin C into a person’s diet, Parris says. In milder cases, that may mean encouraging someone to eat fresh fruits and vegetables that are high in vitamin C, like citrus fruits, tomatoes and broccoli, or having them take a vitamin C supplement.

In more extreme cases, someone may be given vitamin C through an IV infusion before segueing into oral supplements and dietary changes.

“Symptoms usually begin to improve within a few days of proper vitamin C intake, with full recovery occurring within weeks, depending on the severity of the deficiency,” Keatley says.

How to lower the risk of scurvy

The Recommended Dietary Allowance (RDA) for vitamin C for most healthy adults is 75 to 90 milligrams a day, although those who are pregnant or breastfeeding are encouraged to have more. Experts agree that most Americans don’t need to stress about scurvy, but knowing that you could get sick if you don’t have enough fresh produce is important.

“Scurvy is totally preventable with a balanced diet that includes enough vitamin C,” Tinoco says. “As with many health conditions, it’s all about making sure you’re eating a variety of nutritious foods.”

Keatley also recommends keeping this in mind: “The amount of vitamin C needed to prevent scurvy is about two strawberries a day.”