Ascorbic Acid (Vitamin C) Supplement Uses, Benefits, Dosages & Side Effects

L-ascorbic acid (Vitamin C) is a water-soluble vitamin that is best known for its antioxidant properties that help cells to resist damage from free radicals.

It is also known as an immunomodulator that supports the immune system response. This ingredient is also used topically in skin creams to combat signs of aging.

People use L-ascorbic acid supplements to support healthy bones, skin, and joints, for the production of collagen, to support eye health, for heart health, the common cold and more.

Vitamin C is involved with a number of metabolic processes including protein and lipid synthesis, folic acid conversion, cholesterol catabolism, oxidation-reduction reactions, cellular respiration, and the metabolism of both carbohydrates and iron. [1]

This article will discuss what is known about how ascorbic acid works in the body, its common uses, and health benefits, signs of deficiency, food sources, dosages, and side effects.

Vitamin C

Ascorbic Acid Supplement

Skin Health

Immunity

Anti-Oxidant

How It Works:

• Supports white blood cell function
• Required for manufacturing collagen
• Important natural antioxidant protection

Dosage:

Between 500 - 2,000 mg per day

Safety:

Rated Likely Safe

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L-Ascorbic Acid Overview

Vitamin C plays a wide range of roles in the human body. One of its major roles is as an antioxidant that protects cells from oxidative damage and may reduce risk factors for certain health conditions.

Ascorbic acid also helps to regenerate antioxidants in the body, such as alpha-tocopherol (vitamin E).

This vitamin is required for the synthesis of collagen (connective tissue) found in bones, cartilage, muscle, and blood vessels. It also is important for wound healing and skin health.

L-ascorbic acid is a cofactor in the production of various hormones, neurotransmitters, and other compounds in the body. These include norepinephrine, dopamine, l-carnitine, tyrosine, thyroxine, and tryptophan.

It is important for helping the endocrine system to maintain proper hormonal balance. [1] This vitamin is involved in protein metabolism.

If you are deficient in this vitamin, scurvy can result. This is a condition marked by fatigue, weakness in connective tissues and fragility in the capillaries.

Unlike some other mammals, humans cannot biosynthesize ascorbic acid within the body (endogenously). It must be gained from the diet in food sources or from supplements.

Vitamin C is water-soluble and is not stored in significant amounts within the human body. That means it must be consumed on a regular basis from the foods we eat to avoid deficiency.

Ascorbic Acid Health Benefits

The purported health benefits of consuming an L-ascorbic acid supplement include preventing Vitamin C deficiency, supporting detoxification and boosting the immune system.

Thousands of clinical studies have been conducted on ascorbic acid’s biological effects over the past decade.

According to the National Institutes of Health (NIH), most current research is focused on how this nutrient might affect cancer, cardiovascular health, diabetes mellitus, dermatologic health and urinary tract infections.

It is hypothesized that supplementing with this vitamin may improve prenatal health problems, skin wrinkling, vision loss, immune system disorders, and cardiovascular disease. [2]

Collagen Production

Ascorbic acid is necessary for the body to produce an important protein called collagen.

Collagen is the primary structural protein found in the connective tissues of most animals. The well-known food additive gelatin comes from boiling animal collagen. [2]

Collagen is abundant in the skin, hair, and nails. Because ascorbic acid is needed to make collagen, it has been studied for its effects on different dermatological conditions.

In one large study, more than 4000 women between ages 40 and 74 were found to benefit from above-average vitamin C intake. Researchers reported decreased likelihood in these women for developing wrinkled and/or dry skin. [2]

According to one placebo-controlled research study, applying a 3% topical ascorbic acid solution ” resulted in a significant reduction of oxidative stress in the skin, an improvement of the epidermal-dermal microstructure.”

This study also found a significant reduction of fine lines and wrinkles within a short period of time of product application. [3]

Collagen is also used to produce ligaments, tendons and blood vessels as well. Because of this, researchers are exploring the effects of L-ascorbic acid on cardiovascular health.

It has been studied on heart conditions including atherosclerosis (clogged, hardened arteries), peripheral artery disease, hypertension (high blood pressure), and pressure ulcers among various other conditions. [4]

Vitamin C is needed by the body for all stages of wound healing.

It is required from the inflammatory phase when it is needed by the immune system for the production of neutrophils, to the proliferative and maturation stages where it is used for the synthesis of collagen and the formation of scar tissue. [8]

There is also some evidence that topical application of ascorbic acid creams can decrease the redness and swelling (inflammation) expected in various cosmetic procedures such as scar and wrinkle removal surgeries. [4]

Maintaining a healthy diet based largely on raw, organic plants is one way to maintain good levels of the vitamin and minerals necessary to keep the skin and other soft tissues throughout the body healthy.

Vitamin C for Antioxidant Protection

Vitamin C is widely recognized as one of the most important natural antioxidants in the human diet.

Oxidation is a natural process that occurs when unpaired electrons are transferred between molecules. Oxidation occurs naturally both in the body and in the environment.

Oxidation reactions create free radicals, which are unstable, reactive molecules with an unpaired electron. The buildup of these free radicals can cause cellular damage in the body as they move through cells seeking out other electrons to pair with.

Exposure to free radical agents can come from pesticides and herbicides from large-scale farming operations, antibiotics and steroids in meats, water additives like fluorine and chlorine, bread additives like genetically-modified soy, MSG and bromine, industrial pollution, radiation, and smoke.

Over time, these chemicals cause oxidative damage to cells, DNA, and proteins throughout the entire body.

This is known to increase the risk of many degenerative diseases including cancers, diabetes, atherosclerosis, asthma, dementia, joint diseases, and degenerative eye diseases. [9]

Antioxidants are compounds that can inhibit oxidative damage and the production of free radicals. They also work by neutralizing and removing free radicals from the body.

In addition to acting as an antioxidant, the NIH states that ascorbic acid is also capable of restoring the function of certain others antioxidant compounds. [1]

Vitamin C is a potent antioxidant, although not as potent as others including vitamin E and lycopene. However, it may help to recharge Vitamin E and make it more effective in cells.

According to researchers at Oregon State University, Vitamin C provides protection against oxidative stress-induced cellular damage by:

• Scavenging reactive oxygen species (ROS)
• Vitamin E-dependent neutralization of lipid hydroperoxyl radicals
• Protecting proteins from alkylation by electrophilic lipid peroxidation products [4]

Ensuring adequate intake of this important micronutrient is purported to reduce risk factors for developing certain diseases associated with aging.

Nutrient Absorption

Eating a healthy and varied diet is important for the body to function properly. It is also important to be able to extract and assimilate nutrients from foods in the diet so they can be absorbed by the body.

If the digestive system cannot assimilate available nutrients into the bloodstream, symptoms of nutrient deficiency can develop even when dietary consumption is sufficient.

According to SFGate, some vitamins have a synergistic effect with minerals to enhance their absorption and utilization. This is sometimes referred to as bioavailability.

For example, vitamin D enhances the absorption of phosphorus, vitamin K improves calcium utilization and ascorbic acid enhances absorption of iron. [5]

Ascorbic acid helps the cells to take up nonheme iron – the form of iron found in certain plants. Nonheme iron is more difficult for the body to absorb than heme iron, which comes from animal meats.

According to the CDC, iron deficiency is the most prevalent micronutrient deficiency in the world. Increasing your intake of ascorbic acid may improve iron absorption which can support overall health and well-being. [6]

Vitamin C for Cancer

Significant research has investigated the effects of vitamin C can on cancer risk, progression and mortality. NMCD rates ascorbic acid as Possibly Effective for reducing cancer risk.

According to the FDA, “Some scientific evidence suggests that consumption of antioxidant vitamins may reduce the risk of certain forms of cancer. However, FDA has determined that this evidence is limited and not conclusive.”

More research is necessary to determine the therapeutic efficacy of this vitamin for the prevention or treatment of cancer. Initial studies have provided promising results, but the evidence is not definitive.

Dietary consumption of ascorbic acid appears to decrease the risk of developing certain types of cancer. There is also evidence that increasing intake of Vitamin C could reduce the risk of mortality linked to cancer in men.

This vitamin may promote anti-cancer effects through its role as an antioxidant in the body. It has long been hypothesized that antioxidant nutrients may be protective against cancer.

According to the Linus Pauling Institute (LPI), Vitamin C is a necessary cofactor in the synthesis of a group of enzymes called alpha-ketoglutarate-dependent dioxygenases.

In addition to their role in collagen synthesis, these enzymes downregulate a transcription factor called hypoxia inducible factor 1 (HIF1).

HIF1 modulates many genes that control energy production, white blood cell function, cellular apoptosis (natural death), and growth in tumors.

Ascorbic Acid-dependent inhibition of the HIF pathway may provide alternative or additional approaches for controlling tumor progression, infections, and inflammation. [4]

Currently, the data from research on ascorbic acid for cancer is mixed. In case-control and cohort studies it has been observed that diets that are high in fruits and vegetables and consequently vitamin C have been associated with a reduced risk of various cancers such as oral, esophagus, stomach, lung, and colon cancer. [7]

However, observational studies and clinical trials have not demonstrated a protective role of vitamin C supplements against cancer. [7]

If you have cancer concerns and are interested in learning more about ascorbic acid supplementation then speak with your doctor or oncologist for more information.

Ascorbic Acid and Physical Performance

The NMCD has rated ascorbic acid as Possibly Effective for improving physical performance. They state that ascorbic acid might help to enhance physicality by inhibiting the production of histamines, and thereby improving breathing.

In user testimonials, some report that increasing ascorbic acid intake makes them feel more energetic.

One of the ways it may work to support athletic performance is by enhancing iron absorption. Iron is used by the body to transport oxygen through the circulatory system.

Increasing your intake of vitamin C may enhance systemic oxygen delivery to tissues, possibly supporting performance and muscular strength. This effect may be more prominent in elderly people. [7]

The antioxidant and immune-boosting properties of Vitamin C may also support the health of the lungs and airways. This can benefit physical performance by enhancing respiration and oxygen delivery. [7]

More research is needed to determine the effects of ascorbic acid on various markers of physical performance.

Common Vitamin C Uses

Dr. Axe reports that ascorbic acid has also been shown to be helpful for certain other health conditions.

He says that in one study, men over 40 years of age reduced gout risk by 31% in the long term by taking between 1000 mg and 1499 mg of vitamin C daily.

Men over 40 that took more than 1500 mg of ascorbic acid daily reduced long-term gout risk by almost half. [10]

According to the American Journal of Clinical Nutrition, high ascorbic acid levels are inversely associated with risk for ischemic stroke.

In one study, those with the highest Vitamin C levels in their body were found to be 42% less likely to have a stroke than those with the lowest ascorbic acid levels. [10]

The Natural Medicines Comprehensive Database reports that ascorbic acid supplements are also used for:

• Age-related macular degeneration (AMD)
• Allergic rhinitis (hayfever)
• Alzheimer’s disease
• Attention deficit hyperactivity disorder (ADHD)
• Cardiovascular disease
• Cataracts
• Common cold
• Depression
• Diabetes
• Gastritis
• Hypercholesterolemia
• Hypertension (high blood pressure)
• Osteoarthritis
• Osteoporosis
• Stroke
• Sunburn [7]

The NMCD rated ascorbic acid as Effective for vitamin C deficiency and Likely Effective for improving iron absorption.

Vitamin C is rated as Possibly Effective for:

• Age-Related Macular Degeneration AMD
• atherosclerosis & Peripheral Arterial Disease
• Albuminuria
• Atrial Fibrillation
• Bowel Preparation
• Cancer
• Common Cold
• Complex Regional Pain Syndrome
• Contrast-Mediated Nephropathy
• Erythema
• Exercise-Induced Respiratory Infections
• Gallbladder Disease
• Gastritis
• Gout
• Helicobacter Pylori (H. Pylori)
• Hemolytic Anemia
• Hypercholesterolemia
• Hypertension
• Lead Toxicity
• Nitrate Tolerance
• Osteoarthritis
• Physical Performance
• Sunburn
• Wrinkled Skin

Vitamin C has also been studied in a wide range of other conditions. Some uses have preliminary research supporting their efficacy, but are not yet rated for efficacy because clinical data is still limited.

High-dose vitamin C is sometimes prescribed by doctors for certain medical conditions. Injectable vitamin C is an FDA-approved prescription drug.

Most ascorbic acid products are sold as dietary supplements. The FDA has not approved Vitamin C dietary supplements as drugs to prevent or treat any health conditions.

It is recommended that you speak with your doctor if you are interested in learning more about the potential benefits or risks of taking ascorbic acid for a specific health goal.

Ascorbic Acid Deficiency

The National Institutes of Health state that ascorbic acid deficiency is rare in developed countries, but it can still occur in those with a limited variety of foods in their diet.

Vitamin C deficiency symptoms are observed only when intake falls below 10 mg/day for many consecutive weeks. Some evidence suggests that it takes between 84 and 97 days to manifest. [1]

One of the earliest signs of deficiency is fatigue. Other early warnings include decreased motivation, declining psychomotor skills, and changes in personality. [1]

If severe Vitamin C deficiency is not addressed within approximately 4 months, symptomatic scurvy may result.

Scurvy is a condition caused by a chronic lack of ascorbic acid, and the resultant inability to maintain collagen integrity. [1]

Various adverse symptoms can result including loose teeth, swelling and/or bleeding in gums, perifollicular (in/near hair follicles) hemorrhage, hyperkeratosis (thickening skin), petechial (skin capillary) hemorrhage, and/or hemorrhages into leg and arm muscles. [1]

Severe cases of scurvy can progress and cause symptoms including dyspnea (difficulty breathing), neuritis (nerve inflammation), fever, and/or jaundice. [1]

Untreated scurvy will invariably result in death. However, it is very treatable. According to NMCD, “Vitamin C administration can reverse complications of scurvy within 2 days to 3 weeks.” [7]

The NIH states ascorbic acid deficiency does not normally progress far enough to result in scurvy. A mild deficiency is more likely to cause other symptoms including:

• Autoimmune diseases like psoriasis and RA (rheumatoid arthritis)
• Bleeding and/or swollen teeth and gums
• Bruising easily
• Dry, brittle, easy-to-split hair
• Dry red-colored spots on skin
• Frequent nose bleeds
• Inflamed gums (gingivitis)
• Leaky gut syndrome and other digestive disorders
• Painful, swollen joints
• Poor immune system function
• Poor wound healing
• Scaly, rough and/or dry skin
• Slowed metabolism with possible weight gain [1]

Chronic Vitamin C deficiency can also lead to other serious health problems. Low levels of this nutrient can lead to hypertension, ischemic stroke, atherosclerosis, gallbladder disease, and certain types of cancer. [1, 7]

Vitamin C Food Sources

Ascorbic acid is a water-soluble vitamin that cannot be produced within the human body. We must gain this vitamin from our diets either by eating plants that produce it or by taking a supplement.

Vitamin C is found in highest amounts in various vegetables and fruits, especially citrus fruits like lemons, limes, grapefruits, and oranges.

Ascorbic acid is labile, meaning its content in food significantly decreases when cooked or stored. It is recommended to eat organic vitamin C foods fresh, raw, and unprocessed to get the high amounts of this nutrient.

The following are some of the best ascorbic acid food sources to add to your diet:

• 1 whole, raw guava fruit has 375 mg of ascorbic acid
• 1 cup raw Brussels sprouts: 75 mg
• 1 cup raw green pepper: 125 mg
• 1 cup raw red pepper: 185 mg
• 1 cup raw cauliflower: 45 mg
• 1 cup fresh pineapple: 75 mg
• 1 cup black currant: 200 mg
• 1 cup fresh parsley: 80 mg
• 1 cup raw broccoli: 80 mg
• 1 cup of grapefruit: 70 mg
• 1 cup strawberries: 90 mg
• 1 cup raw kale: 80 mg
• 1 large orange: 80 mg
• 1 cup papaya: 85 mg
• 1 kiwi fruit: 165 mg

You should try to consume at least 2 or 3 of these foods each day to ensure adequate intake of this vitamin.

Foods in their natural states provide the body with the best sources of ascorbic acid and various other essential nutrients.

Ascorbic Acid Supplements

Many health professionals agree that when it is possible, nutrients should be gained from a diverse diet based mainly on fresh, organic plants.

However, this is not possible for some people due to various circumstances, and in these cases ascorbic acid supplements may be useful.

If you choose to take a vitamin C supplement instead of or in addition to elevating your levels from your diet, then it is recommended to consider high-quality supplements that are free of additives, fillers, and/or synthetic ingredients.

The NMCD states that there are over 30,000 dietary supplements available that contain vitamin C as a single ingredient or as part of a multivitamin. This means that there is a large variety of choices, but also a range of quality.

Look for high quality supplements that are produced by reputable manufacturers that follow cGMP guidelines and perform third-party laboratory testing of ingredients.

Supplements are available as sodium ascorbate, calcium ascorbate, potassium ascorbate, magnesium ascorbate, manganese ascorbate, and liposomal vitamin C.

Vitamin C supplements are available as tablets, caplets, capsules, powders, lozenges, liquid drops, and other forms. The most common supplements are available in 500 mg and 1000 mg formulations.

Supplements often contain other ingredients including iron, copper, zinc, rose hips, buckwheat, and various others. Look for supplements with organic ingredients when possible.

Many supplements also contain artificial coloring, flavoring, and/or preservatives. Sources recommended avoiding unnecessary intake of these additives.

Ascorbic Acid Dosages

The NIH reports the following recommended daily intake amounts for ascorbic acid in healthy people:

• 40 mg/day for infants between 0 and 6 months
• 50 mg/day for infants between 7 and 12 months
• 15 mg/day for children between 1 and 3 years
• 25 mg/day for children between 4 and 8 years
• 45 mg/day for children between 9 and 13 years
• 65 mg/day for girls between 14 and 18 years
• 80 mg/day for teens who are pregnant
• 115 mg/day for teens who are breastfeeding
• 75 mg/day for boys between 14 and 18 years
• 90 mg/day for men 19 and older
• 75 mg/day for nonpregnant, non-nursing women 19 and older
• 85 mg/day for pregnant women
• 120 mg/day for women who are breastfeeding

The NIH states that people who smoke tobacco products and those who live in close proximity to smokers should increase their intake by 35 mg/day in addition to the recommended amounts listed above.

As a water-soluble vitamin, excess amounts of this compound that build up in the body are excreted in the urine. Vitamin C overdose is not a common concern.

he upper tolerable limit (UL) for ascorbic acid is 2000 mg daily. Consuming less than this amount is not likely to cause adverse reactions.

As a dietary supplement, it is most typically taken in dosages of 1000 mg per day.

The NMCD reports that in research studies on the antioxidant effects of ascorbic acid, it has been used at dosages of 200-1000mg per day from four weeks to one year with no reported adverse effects.

The NMCD states that studies on cancer prevention have used dosages of 120-2000 mg daily. One study used 500 mg of vitamin C for 6-8 years.

For prevention and treatment of the common cold, dosages between 30-3000 mg have been studied.

Dosages above the UL of 2000 mg per day should only be taken under the advice of a doctor. You should speak to your doctor about the best dosage of this supplement for your needs.

Ascorbic Acid Safety and Side Effects

The NMCD rates ascorbic acid as Likely Safe when used orally, topically, intramuscularly, or intravenously and appropriately.

Oral dosages should be taken below the UL of 2000 mg per day. The NMCD has rated vitamin C as Possibly Unsafe if used orally in excessive dosages.

The potential side effects increase with use of higher dosages. The most common side effects people experience include:

• Nausea
• Vomiting
• Dyspepsia (Heartburn)
• Stomach Cramps
• Gastrointestinal Obstruction
• Insomnia
• Flushing
• Headache
• Sleepiness
• Fatigue

When daily doses exceed 2000 mg per day, more serious side effects including severe gastrointestinal upset and osmotic diarrhea can occur.

When used topically, ascorbic acid creams might cause tingling or irritation at the site of application.

Drug & Supplement Interactions

Ascorbic acid can interact with some medications, herbal extracts, health conditions, and laboratory tests.

Seek medical advice and use extra caution before taking this supplement with any of the following:

• Aluminum; ascorbic acid increases aluminum absoprtion
• Blood thinners; it might decrease their effectiveness
• Diuretics; they can increase urinary loss of Vitamin C
• Estrogens; ascorbic acid might slow down their metabolism
• Some cancer medications; it might reduce their effectiveness

There are other medicines that ascorbic acid may interact with. If you take prescription medications, ask your doctor before taking Vitamin C supplements.

Ascorbic acid may interact with the following herbs and supplements:

• Acerola
• Cherokee Rosehip
• Chromium
• Copper
• Grape Seed Phenols
• Niacin
• Rosehip
• Vitamin B12

This supplement can cause harmful effects when used in people with certain health conditions. Some of these include cancer, diabetes, kidney stones, renal transplant, and sickle cell disease.

Tell your doctor about any supplemental vitamin C usage if you are scheduled to take any type of laboratory test. It can alter results when testing levels of acetaminophen, calcium, sodium, bilirubin, iron, theophylline, vitamin B12, and others.

It is best to consult with a medical professional before increasing intake of ascorbic acid-rich foods or beginning to take a supplement.

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