10 Health Benefits of Vitamin C
By Eric Madrid, MD
In this article:
Vitamin C, also known as ascorbic acid or ascorbate, has been one of the most researched vitamins over the last 50 years. A search of the scientific literature reveals that over 53,000 studies have been conducted on vitamin C since 1968. Their findings show that it helps promote a strong immune system as well as cardiovascular, brain, and skin health among many others benefits.
Many scientists believe that at one time the human body had the ability to make vitamin C, but lost this capacity over time. Essentially, all species of animals, including most mammals, can make vitamin C—the exceptions are humans, monkeys and guinea pigs. The brain and adrenal glands have the highest concentrations of vitamin C, 15 to 50 times higher than that found in the blood. This makes sense when one realizes that vitamin C was first discovered by Albert Szent-Györgyi in 1928 while he was conducting research on the adrenal glands. Vitamin C, which has antioxidant properties, is also an enzyme “co-factor” for at least eight important biochemical reactions.
According to a 2009 study in The American Journal of Clinical Nutrition, over seven percent of people age six and older were vitamin C deficient when their blood was tested. More than half of those surveyed consumed low amounts of vitamin C rich foods. In the last five years, I diagnosed three patients with scurvy, a disease that was traditionally diagnosed in British sailors who had limited access to fresh fruit.
My first patient with scurvy was a 40-year-old woman who smoked (Vitamin C levels are lower in those who smoke tobacco) and admitted to a poor diet. She was concerned about her bleeding gums and easy skin bruising. After her dentist confirmed the absence of gum disease, I ordered a blood test which confirmed a vitamin C deficiency, leading to the diagnosis of scurvy. Her bleeding gums and bruising symptoms improved after a few weeks of vitamin C supplementation. The other two patients also had significant bruising as their initial symptom.
Risks Factors of Vitamin C Deficiency
- Poor diet
- Low consumption of fruits and vegetables
- Tobacco smoking (each cigarette oxidizes about 60 mg of vitamin C)
Symptoms of Vitamin C Deficiency
- Bleeding gums
- Joint pain
- Bone pain
- Muscle aches
Food Sources of Vitamin C
- Brussel sprouts
Health Benefits of Vitamin C
Anemia due to iron deficiency is common. It can occur in women who have heavy menses or may occur in individuals with hemorrhoids, colon polyps or even worse, colon cancer. Once the cause is identified, a physician may recommend iron supplementation. When taking iron, vitamin C should also be taken as this will help improve absorption of the iron and help reduce the constipation side effect of iron.
In the 1970s, two-time Nobel prize winner Linus Pauling theorized that high dose vitamin C
could help prevent and treat cancer. There has been a lot controversy regarding his claims ever since. In the lab, vitamin C has been shown to kill various cancer cells. However, when taken orally, the benefits have not been as strong. Several studies have shown that intravenous vitamin C can elevate blood levels more than oral dosing and overall is well tolerated by cancer patients. However, few doctors will administer vitamin C intravenously, a service usually only provided by integrative medicine physicians.
A 2018 study which included more than 24,000 people showed those with higher vitamin C blood levels were 42 percent less likely to have esophageal cancer and also less likely to have Barrett’s esophagus, the precancerous condition.
Cataracts are a clouding of the lens that occurs as one ages. The good news is this can be prevented. A 2013 study showed that a diet high in fruits, vegetable and vitamin C could help prevent cataracts from forming.
Vitamin C plays a significant role in collagen formation, the main component of arteries and skin. Collagen is also important to keep teeth healthy. Studies show a diet high in foods containing vitamin C are good for the skin, teeth and bones. Consuming a diet rich in vitamin C is a good way to optimize this important antioxidant. Consumption of vitamin C also has many skin benefits—a 2018 study in which vitamin C was taken orally along with collagen protein showed significant improvement in skin health after only 12 weeks.
In addition, application of topical vitamin C directly to the face and other parts of the body is helpful in protecting the skin against solar damage, according to studies.
As one ages the risk for heart disease, which can result from clogged arteries and also manifest itself in the form irregular heartbeats (sometimes resulting in the need for a pacemaker), increases. The choices we make on a daily basis will impact the future version of ourselves. Eating well is important as studies show a diet high in vitamin C-rich foods is good for the heart while smoking cessation can also have heart-healthy benefits—non-tobacco smokers have vitamin C blood levels that are 4.3 times greater than that of smokers. This likely explains why smoking increases one’s risk for heart disease and accelerates aging.
Clogged arteries are also known as arteriosclerosis, a condition where blood flow is affected. A 2017 study in the Journal of Nutritional Biochemistry demonstrated that rose hips, which are rich in vitamin C, helped prevent atherosclerosis, an early indicator of heart disease. Atrial fibrillation is a heart condition that is diagnosed when the heart has an irregular beat. The risk for this condition increases as one ages and also can occur after a person undergoes a heart surgery. A 2018 study in Clinical Cardiology showed that patients given vitamin C after heart surgery were less likely to develop atrial fibrillation when compared to those not given vitamin C.
Vitamin C may also be helpful for maintaining memory, a concern many have. Dr. Dale Bredesen from the University of California Los Angeles (UCLA) has put together a comprehensive protocol in his 2017 book The End of Alzheimer’s Disease. Vitamin C is one of the supplements he recommends among other supplements as part of his natural approach to Alzheimer’s Disease.
A 2018 animal study testing memory showed that rats exposed to tobacco smoke had poor memory. However, when rats were given vitamin C prior to being exposed to the tobacco smoke, their memory improved. In addition, a 2015 study showed that sleep-deprived rats given vitamin C had better memory recall when compared to sleep-deprived rats not given vitamin C. It is believed that the vitamin C helps prevent oxidative damage to the hippocampus, the part of the brain involved in memory.
Gum and tooth disease is a leading risk factor for heart disease. The more gum disease one has, the higher the risk one has for having a heart attack. A 2018 study shows that vitamin C plays an important role in gum health while a 2015 study showed that vitamin C also plays an important role in gum health of the elderly.
Vitamin C, also known as ascorbic acid, has been recommended to help prevent the common cold for decades. To this day there still is no cure for the common cold, but a 2014 study showed that vitamin C could reduce risk for developing a cold and also reduced the duration of the cold when compared to placebo (sugar pills). Other studies have shown those under physical stress we're more likely to prevent the cold with vitamin C. More studies, however, are needed. Suggested Dose: 500 mg to 2,000 mg daily.
A blood infection, or sepsis, can result in severe illness and sometimes death. The infection can start anywhere in the body, but frequently a blood infection starts from an infection in the lungs (pneumonia), urine (urinary tract) or skin. A 2018 study showed the intravenous vitamin C, when given with vitamin B1 and steroids could help prevent organ damage in those with sepsis. A 2018 study in the Journal of Critical Care showed that vitamin C could help reduce inflammation in those with blood infections. More studies are underway, and this therapy is being further evaluated before it becomes accepted by healthcare professionals.
A 2018 study showed that those with epilepsy, a seizure disorder, were more likely to have nutritional deficiencies, including a vitamin C deficiency. This may be due to the medications used to treat epilepsy.
There have been a few case reports of vitamin C supplementation increasing the risk for kidney stones. However, this is rare. Those with pre-existing kidney stones should avoid taking vitamin C in excess of 1,000 mg due to possible risk of increasing oxalate production and calcium oxalate from building up in the kidneys. In addition, those with iron overload or hemochromatosis should be careful since vitamin C increases absorption of iron in the intestinal tract. Consult with your physician if you are unsure.
Daily aspirin use appears to lower vitamin C levels. Daily supplementation with vitamin C should be considered. In addition, chronic oral steroid (i.e. prednisone) use lowers vitamin C blood levels as do routine use of stomach acid reducing medications.
Vitamin C Capsules/Tablets – 250 mg to 2,000 mg per day
Vitamin C Powder- 250 mg to 2,000 mg per day
Vitamin C Gummies - 250 mg to 2,000 mg per day
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