A healthy immune system depends on the intake of essential vitamins, yet many of us lack the nutrients we need for overall wellness. It may be because we don’t eat a balanced diet, or we may suffer from a condition like Crohn’s disease that makes it difficult to absorb vitamins. A study published in the journal Nutrients found that “nutrient inadequacies can impair immune function and weaken the immune response.”

Vitamin C is an important nutrient needed for growth and development, according to Eat This, Not That! It’s needed to grow and repair tissue, to aid in healing wounds, and is an antioxidant that protects our cells from free radical damage. It’s also a powerful antiviral that helps ward off colds, flu and even COVID-19.

Dr. Donald Marks, an internist and infectious disease expert with degrees in both immunology and microbiology, says that vitamin C is important for preventing and treating COVID-19.

“We are testing many therapies to treat this virus, and, in my opinion, vitamin C is one of the best options,” he tells Newsmax. “It is an antiviral and is readily available not only in fruits and vegetables, but in a variety of over-the counter supplements, as well as in throat lozenges and gummies.”

According to Harvard T.H. Chan School of Public Health, “Vitamin C plays a role in controlling infections and healing wounds. It is needed to make collagen, a fibrous protein in connective tissue that is weaved throughout various systems in the body: nervous, immune, bone, cartilage, blood, and others. The vitamin helps make several hormones and chemical messengers used in the brain and nerves.”

Health coach Lindsay Tullis says that the recommended daily intake for vitamin C varies with age and gender. The RDI for adult males is 90 milligrams per day, and for woman the RDI is 75 milligrams daily. According to Healthline the most common risk factors for vitamin C deficiency are poor diet, alcoholism, anorexia, severe mental illness, smoking and dialysis.

Here are some signs that you may be deficient in Vitamin C and should ask your doctor to check your blood levels of this important vitamin:

• Rough, bumpy skin. When vitamin C levels are low, it interferes with collagen production and can cause a skin condition called keratosis pilaris. In this condition, you may find bumpy “chicken skin” on the back of upper arms, thighs, or buttock due to a buildup of keratin protein inside the pores.  The condition usually resolves with supplementation.

• Corkscrew-shaped body hair. Corkscrew-shaped hair is one of the hallmark signs of vitamin C deficiency and the abnormality often resolve within one month of treatment with vitamin C supplementation.

• Spoon-shaped fingernails with red spots or lines. Spoon-shaped nails are associated with iron deficiency anemia, but their presence has also been linked to vitamin C deficiency.

• Dry, damaged skin. Healthy skin is composed of large amounts of vitamin C, especially the epidermis, or outer layer. High intakes of vitamin C are associated with better skin quality, says Healthline, while lower intakes are associated with an increased risk of developing dry, wrinkled skin.

• Frequent bruising. When the blood vessels under the skin rupture, leading blood to leak into surrounding areas, it results in bruising. Easy bruising is a common sign of vitamin C deficiency since poor collagen production causes weak blood vessels.

• Fatigue and poor mood. Two of the earliest warning signs of vitamin C deficiency are feeling tired and out of sorts. These symptoms can occur before a full-blown deficiency develops but can be reversed quickly with adequate vitamin C intake.

The foods that can help boost vitamin C levels include acerola cherry, guava, blackcurrants, sweet red pepper, kiwifruit, citrus fruits, strawberry, papaya, broccoli, and parsley.