Vitamin C: Top Benefits, Sources & Supplements in 2024

Do you need to take vitamin C supplements, and how much is enough? The answer may depend on your age and overall health.

Vitamin C is a water-soluble vitamin with a variety of benefits, but our bodies can’t make it. We need to consume it through the food we eat or by supplementation. Vitamin C is a vital nutrient that plays numerous roles in maintaining overall health. From enhancing your immune system to promoting radiant skin, Vitamin C is crucial for optimal well-being.  

This article explores what vitamin C does, top benefits of Vitamin C, where we can get it, how much vitamin C is the right amount and who may need to take supplements including those popular in Pakistan.

What is Vitamin C?

Vitamin C, also known as Ascorbic acid or L-ascorbic acid, is a water-soluble vitamin that acts as a powerful antioxidant. It helps protect cells from damage caused by free radicals and supports various bodily functions. Unlike some vitamins, Vitamin C cannot be stored in the body, which makes regular consumption essential.

How Much Vitamin C is Enough? 

Vitamin C is one of the safest and most effective nutrients. Though it may not be the cure for the common cold, the benefits of Ascorbic acid may include protection against immune system deficiencies, cardiovascular disease, prenatal health problems, eye disease, and even skin wrinkling. Sensitive Skin Saviors: 7 Steps to the Best Skincare Routine provides additional insights on maintaining your skin’s health, which could be especially helpful when looking at the skin benefits of Vitamin C.

The tolerable upper intake level (or the maximum amount you can take in a day that likely won’t cause harm) is 2,000 milligrams (mg)a day for adults.

Oral vitamin C produces tissue and plasma concentrations that the body tightly controls. Approximately 70%–90% of vitamin C is absorbed at moderate intakes of 30–180 mg/day. However, at doses above 1 g/day, absorption falls to less than 50% and absorbed, unmetabolized ascorbic acid is excreted in the urine [4].

Results from pharmacokinetic studies indicate that oral doses of 1.25 g/day ascorbic acid produce mean peak plasma vitamin C concentrations of 135 micromole/L, which are about two times higher than those produced by consuming 200–300 mg/day ascorbic acid from vitamin C-rich foods [10]. Pharmacokinetic modeling predicts that even doses as high as 3 g ascorbic acid taken every 4 hours would produce peak plasma concentrations of only 220 micromole/L [10].

The total body content of Ascorbic acid ranges from 300 mg (at near scurvy) to about 2 g [4]. High levels of vitamin C (millimolar concentrations) are maintained in cells and tissues and are highest in leukocytes (white blood cells), eyes, adrenal glands, pituitary gland, and brain. Relatively low levels of vitamin C (micromolar concentrations) are found in extracellular fluids, such as plasma, red blood cells, and saliva [4]. 

Table 1: Recommended Dietary Allowances (RDAs) for Vitamin C

The Role of Ascorbic acid in the Body

Vitamin C, also known as ascorbic acid, is necessary for the growth, development and repair of all body tissues. It’s involved in many body functions, including formation of collagen, absorption of iron, the proper functioning of the immune system, wound healing, and the maintenance of cartilage, bones and teeth. It is one of many antioxidants that can protect against damage caused by harmful molecules called free radicals, as well as toxic chemicals and pollutants like cigarette smoke. Free radicals can build up and contribute to the development of health conditions such as cancer, heart disease and arthritis.

The body doesn’t store it, so overdose is not a concern. But it’s still important not to exceed the safe upper limit of 2,000 milligrams a day to avoid stomach upset and diarrhea. L-ascorbic acid is one of the “water-soluble” vitamins. Because your body doesn’t store them, you need to keep them in your diet all the time to maintain healthy levels. Eat vitamin-C-rich fruits and vegetables raw, or cook them with minimal water so you don’t lose some of the water-soluble vitamin in the cooking water. 

Antioxidant Protection:

It neutralizes free radicals, reducing oxidative stress and preventing cell damage.

Collagen Synthesis:

It is crucial for the production of collagen, a protein that helps maintain skin elasticity and firmness.

Immune Support:

Vitamin C enhances the immune system’s function, aiding in the prevention of infections and illnesses.

Top Benefits of Vitamin C

No one vitamin can override serious health problems. They often work together – and other lifestyle habits – like getting enough sleep and exercise, and not smoking – are key. That said, research shows that it may offer health benefits in these areas:

1. Boosts Immune System

It is renowned for its role in enhancing the immune system. It stimulates the production of white blood cells, which are essential for fighting infections. According to a study published in the *American Journal of Clinical Nutrition*, L-ascorbic acid can shorten the duration of common colds by about 8% in adults and 14% in children.

2. Promotes Healthy Skin

Vitamin C is a key ingredient in many skincare products due to its ability to support collagen production. Regular use can help reduce wrinkles, fine lines, and improve overall skin texture. For instance, **Bio One Vitamin C Serum** is a popular product that combines it with other beneficial ingredients to enhance skin health. For more on maintaining healthy skin, consider reading more about dry skin causes, symptoms, and best remedies.

3. Supports Heart Health

It helps in reducing the risk of heart disease by improving endothelial function, which is essential for proper blood vessel health. A study in the *Journal of the American Heart Association* suggests that higher Ascorbic acid intake is associated with a lower risk of cardiovascular diseases. 

4. Enhances Iron Absorption

Vitamin C improves the absorption of iron from plant-based foods. This is particularly beneficial for individuals following a vegetarian or vegan diet. Consuming L-ascorbic acid-rich foods alongside iron-rich foods can increase iron absorption by up to 30%.

5. Reduces Risk of Chronic Diseases

Antioxidants like Vitamin C play a role in reducing inflammation and oxidative stress, which are linked to chronic diseases such as diabetes and cancer. Regular intake of Vitamin C can help lower the risk of developing these conditions.

6. Improves Mood and Cognitive Function

Vitamin C is involved in the synthesis of neurotransmitters, which are chemicals that transmit signals in the brain. Adequate levels of L-ascorbic acid are associated with improved mood and cognitive function. A study in the *Journal of Clinical Psychiatry* found that Ascorbic acid supplementation can help reduce symptoms of depression and anxiety.

7. Stress

A deficiency in vitamin C is associated with many stress related disease. It is the first nutrient to be depleted in people who drink too much alcohol, smoke, or have obesity. And because L-ascorbic acid is one of the nutrients sensitive to stress, Moyad says maintaining levels of it can be an ideal marker for overall health.

8. Colds

When it comes to the common cold, it is not a cure, but some studies show that it may help prevent more serious complications. “There is good evidence taking L-ascorbic acid for colds and flu can reduce the risk of developing further complications, such as pneumonia and lung infections,” says Moyad.

9. Stroke

Although research has been conflicting, one study in the American Journal of Clinical Nutrition found that those with the highest concentrations of Ascorbic acid in their blood were associated with 42% lower stroke risk than those with the lowest concentrations. The reasons for this are not completely clear. But what is clear is that people who eat plenty of fruits and vegetables have higher blood levels of it.

“People who consume more fruit and vegetables will not only have higher [blood] levels of vitamin C, but higher intake of other nutrients potentially beneficial to health, such as fiber and other vitamins and minerals,” study researcher Phyo K. Myint said in an email interview.

10. Skin Aging 

It affects cells on the inside and outside of the body and it’s antioxidant properties can be beneficial when it comes to aging. A study published in the American Journal of Clinical Nutrition examined links between nutrient intakes and skin aging in 4,025 women aged 40-74. It found that higher L-ascorbic acid intakes were associated with a lower likelihood of a wrinkled appearance, dryness of the skin, and a better skin-aging appearance. In addition, topical treatments with Ascorbic acid have been shown in some studies to reduce wrinkles.

Unproven claims about vitamin C

While vitamin C has many scientifically proven benefits, it also has many unfounded claims supported by either weak evidence or no evidence at all. Here are some unproven claims about vitamin C:

• Reduces cancer risk. A handful of studies have linked it intake to a lower risk of several cancers. However, most studies have found that it does not affect the risk of developing cancer.
• Protects against eye disease. Ascorbic acid has been linked to reduced risks of eye diseases like cataracts and age-related macular degeneration. However, vitamin C supplements have no effect or may even cause harm.
• May treat lead toxicity. Although people with lead toxicity appear to have low vitamin C levels, there is no strong evidence from human studies that show it can treat lead toxicity.

Sources of Vitamin C

Fruits and vegetables are the best sources of it (see Table 2) [12]. Citrus fruits, tomatoes and tomato juice, and potatoes are major contributors of L-ascorbic acid to the American diet [8]. Other good food sources include red and green peppers, kiwifruit, broccoli, strawberries, Brussels sprouts and cantaloupe (see Table 2) [8,12].

Although it is not naturally present in grains, it is added to some fortified breakfast cereals. The vitamin C content of food may be reduced by prolonged storage and by cooking because ascorbic acid is water soluble and is destroyed by heat [6,8]. Steaming or microwaving may lessen cooking losses.

Fortunately, many of the best food sources of vitamin C, such as fruits and vegetables, are usually consumed raw. Consuming five varied servings of fruits and vegetables a day can provide more than 200 mg of vitamin C.

Table 2: Vitamin C Content of Selected Foods 

1. Fruits

Citrus Fruits:

Oranges, lemons, and grapefruits are excellent sources.

Kiwifruit:

Contains more Ascorbic acid than an equivalent amount of oranges.

Strawberries:

Rich in L-ascorbic acid and antioxidants.

2. Vegetables

Bell Peppers:

Red bell peppers have a high concentration of Ascorbic acid.

Broccoli:

A nutrient-dense vegetable that provides a significant amount of L-ascorbic acid.

Spinach:

Also provides Ascorbic acid along with other essential nutrients.

3. Supplements

Vitamin C Tablets:

Easily available and come in various formulations, including those with added zinc for enhanced benefits.

Vitamin C Drink:

Convenient for those who prefer liquid supplements. Products like CAC 1000 Plus offer a combination of Vitamin C and other beneficial nutrients.

Best Vitamin C Supplements in Pakistan

In Pakistan, several high-quality Vitamin C supplements are popular among consumers:

Bio One Vitamin C Serum:

A favorite for skincare enthusiasts.

CAC 1000 Plus:

Offers a high dose of L-ascorbic acid and is well-regarded for its effectiveness.

Vitamin C and Zinc Tablets:

Commonly used for enhanced immune support.

Vitamin C and Other Nutrients

1. Vitamin C and Zinc

Combining Vitamin C with zinc can boost immune function and enhance skin health. Studies show that this combination can reduce the duration of common colds and support overall immune health.

2. Vitamin C and Calcium

While Vitamin C and calcium do not interact directly, they both contribute to overall health. Ascorbic acid helps in the absorption of calcium and supports bone health.

Health Risks from Excessive Vitamin C

It has low toxicity and is not believed to cause serious adverse effects at high intakes. The most common complaints are diarrhea, nausea, abdominal cramps, and other gastrointestinal disturbances due to the osmotic effect of unabsorbed L-ascorbic acid in the gastrointestinal tract.

In postmenopausal women with diabetes who participated in the Iowa Women’s Health Study, supplemental (but not dietary) vitamin C intake (at least 300 mg/day) was significantly associated with an increased risk of cardiovascular disease mortality.

However, studies evaluating the effects on urinary oxalate excretion of it intakes ranging from 30 mg to 10 g/day have had conflicting results, so it is not clear whether vitamin C actually plays a role in the development of kidney stones. The best evidence that it contributes to kidney stone formation is in patients with pre-existing hyperoxaluria.

Due to the enhancement of nonheme iron absorption by vitamin C, a theoretical concern is that high vitamin C intakes might cause excess iron absorption. In healthy individuals, this does not appear to be a concern. Under certain conditions, L-ascorbic acid can act as a pro-oxidant, potentially contributing to oxidative damage.

A few studies in vitro have suggested that by acting as a pro-oxidant, supplemental oral vitamin C could cause chromosomal and/or DNA damage and possibly contribute to the development of cancer. However, other studies have not shown increased oxidative damage or increased cancer risk with high intakes of ascorbic acid. 

Other reported effects of high intakes of L-ascorbic acid include reduced vitamin B12 and copper levels, accelerated metabolism or excretion of ascorbic acid, erosion of dental enamel, and allergic responses. However, at least some of these conclusions were a consequence of assay artifact, and additional studies have not confirmed these observations.

Conclusion

L-ascorbic acid is an essential nutrient with a range of benefits for your health, from boosting your immune system to improving skin texture. By incorporating Vitamin C-rich foods into your diet or using supplements, you can support your overall well-being. 

Don’t let your health take a backseat—take action today to include Vitamin C in your daily routine for a healthier, more vibrant you!

Feel free to reach out if you have any questions or need further assistance with your Vitamin C needs. Your journey to optimal health starts now!