In a recent blog, we discussed proline and hydroxyproline as amino acid constituents of collagen and we talked about the key roles they play in collagen stability, and ultimately, in skin beauty. It’s important to know that a vitamin C deficiency leads to reduced collagen stability because this deficiency causes a decrease in the conversion rate of proline to hydroxyproline. Vitamin C, required for more than 300 different functions in the body, is an indispensable co-factor supporting the functioning of enzymes that are required for collagen formation. Vitamin C’s number one purpose is to support collagen synthesis.
Delayed wound healing is a feature of vitamin C deficiency. Scurvy(1)—where wounds won’t heal or old wounds reopen—is an advanced condition of vitamin C deficiency.
Collagen produces scar tissue and heals wounds. If you are wounded or are about to undergo surgery you need to increase your intake of vitamin C to not only help you heal but fight off infections. Increased vitamin C consumption will also make you less likely to develop bed sores if you’re bedridden since the collagen under your skin will now be stronger.
Patients with normal nutritional status demonstrate higher amounts of normal collagen (measured by hydroxyproline content) while those with malnutrition show significantly lowered collagen formation.
The Action of Vitamin C in Collagen Synthesis
In our earlier blog on proline and hydroxyproline amino acids we discussed the triple helix formation of collagen molecules. We said:
“Each chain in the helix is more than 1400 amino acids long. A repeated sequence of three amino acids forms this sturdy structure. Every third amino acid is glycine … while many of the remaining positions in the chain are filled by proline and hydroxyproline.”
For these three peptides(2) to be able to form a stable helix, a significant number of proline residues in the peptide chain have to be hydroxylated(3) by the enzyme prolyl hydroxylase. In other words, some proline residues are hydroxylated to become hydroxyproline.
This legendary nutrient, vitamin C, is vital to hydroxylation—the process by which collagen strands build stability.
This is how vitamin C works to stimulate collagen synthesis. It should be noted that elastin, another protein found in elastic tissues, also requires vitamin C for synthesis.
Vitamin C is Water Soluble
Humans don’t manufacture vitamin C and we don’t store it longterm. Since vitamin C is water soluble, it is excreted renally and must be frequently replenished.
Fortunately, vitamin C is abundant in so many common fruits and vegetables that almost everyone gets enough vitamin C to at least prevent scurvy (mentioned above and further described in endnotes below). Nevertheless, studies of typical American diets demonstrate that most people barely reach the RDA of 75 mg a day for an adults female and 90 mg for a man. Many nutritionists prefer 250 mg a day for their clients.
A healthy adult body contains about 5,000 mg of vitamin C. If you decide to supplement your body with vitamin C in capsule form, you’ll begin to eliminate excess vitamin C only after you’ve reached the 5,000 mg saturation point and only if you’re in perfectly good health.
Outward Symptoms of Vitamin C Deficiency
• dry hair
• appetite loss
• bleeding gums
• loose teeth
• easy to bruise
• muscle weakness
• sore joints
• general fatigue
• too tired to eat properly
• frequent infections
• slow wound healing
• decreased ability to fend off infection
While some of the above symptoms can have other root causes, the one telltale symptom across the board for vitamin C deficiency is easy bruising.
Stable collagen is needed for healthy blood vessels and an inadequate amount of vitamin C in the body weakens the walls of your blood vessels causing them to break easily forming bruises and even nosebleeds. It has been found that supplementing the diet with 500 mg of vitamin C per day can make you feel better within a week or so and stop bruising.
At Risk Groups for Vitamin C Deficiency and Collagen Instability
• Smokers: Cigarette smoke breaks vitamin C down quickly and damages your cells.
• Diabetics: People with diabetes are challenged to absorb vitamin C.
• Asthmatics: Fighting asthma attacks uses up your vitamin C.
• Allergy sufferers: Combatting symptoms of allergies also uses up whatever stores you have of vitamin C.
• People sick with cold or flu: When fighting colds and flu, your immune system demands tons of vitamin C.
• Post-operative patients: The body demands a great deal of vitamin C to heal after surgery.
• Those suffering from physical stress: Under stress, your body goes into “overdrive” and uses up whatever vitamin C stores you have.
• Those suffering from psychological stress: This is the same as for physical stress sufferers mentioned just above.
• Elderly persons: As people age, in general, we just need more vitamin C than we used to need for all the various functions vitamin C facilitates, most especially supporting collagen integrity.
• Pregnant and breastfeeding mothers: Sharing your vitamin C with baby means you need to consume much more of it.
• People who take drugs that block vitamin C absorption: These drugs include aspirin, birth control pills, antibiotics and a number of steroids.
• Alcoholics: Not only does alcohol destroy vitamin C, those who abuse alcohol do not eat well enough to get very much vitamin C.
Food Sources of Vitamin C Other Than Commonly Known Citrus Fruits
• Acerola berries: These tart berries have the richest vitamin C content of all fruits and vegetables. One cup contains 1600 mg of vitamin C compared to just 80 mg for a medium sized orange. But because of their extreme tartness, they’re juiced and converted to powder to be used in supplements. You won’t be able to find the berries sold as whole berries in the market.
• Kiwis: Kiwis contain as much vitamin C content as an orange.
• Spinach and kale: These dark leafy greens have fairly good amounts of vitamin C.
• Peppers: All kinds of peppers are very high in vitamin C. One cup of chopped yellow bell pepper contains approximately 340 mg of vitamin C while the same amount of green bell pepper contains 45 mg. Sweet bell peppers have higher amounts of vitamin C than hot.
• Broccoli and brussels sprouts: They contain 58 and 48 mg per cup, respectively.
• Cantaloupe: One cup of diced cantaloupe contains 68 mg of vitamin C.
• Guava: One medium sized guava gives you 165 mg of vitamin C.
• Papaya: One medium sized papaya gives you 188 mg of vitamin C.
• Mango: One medium sized mango offers 57 mg.
• Strawberries: One cup of fresh strawberries contains 85 mg of vitamin C.
There are quite small amounts of vitamin C in animal products, zero in grains and just a minute amount in beans. Fruits and vegetables are your best go-to source for bioavailable vitamin C, with fruits being your absolute best most abundant source.
Did You Know?
Frozen vegetables contain almost as much vitamin C as fresh vegetables do. Freezing actually preserves most of the vitamin C in vegetables.
But canned vegetables have little to no vitamin C to offer you since the vegetables are cooked and then packed in water. This process destroys the vitamin C.
When it comes to fruit, much of the vitamin C content is preserved in freezing but not as much as for vegetables for some reason. And canned fruits, similar to canned vegetables, have almost no vitamin C to offer you.
Collagen Supporting Nutrition
Foods rich in vitamin C, antioxidants and omega 3 fatty acids have been proven to significantly support the body’s production of collagen whiling guarding the body against the somewhat inevitable loss of collagen.
While we can always augment our diets with supplements, the very best most bioavailable sources for vitamin C and many other nutrients are first and foremost, our food.
We need collagen to fix damage to our bodies. Collagen is the glue that basically holds the body together but we can’t make it or maintain it unless we consume adequate amounts of vitamin C. Focus on making vitamin C rich fruits and vegetables a part of your daily diet for firmer skin, healthy bones and joints, and overall better health and vitality.
1. Scurvy: A vitamin C deficiency disease characterized by fragility of the blood vessel walls and small subcutaneous hemorrhages around hair follicles; also inflammation of gums and loss of dental cement, and hence, loss of teeth; also poor healing of wounds
2. Peptide: a compound consisting of two or more amino acids linked in a chain
3. Hydroxylation is the process whereby a hydroxyl group (of or denoting the radical–OH, present in alcohols and many other organic compounds) is introduced into a molecule or compound.
• Handbook of Nutrition in the Aged. United Kingdom, CRC Press, 2019.
• Molecular Nutrition. United Kingdom, CABI Pub., 2003.
• Pressman, Alan H., and Buff, Sheila. The Complete Idiot's Guide to Vitamins and Minerals. United Kingdom, Alpha, 2000.
• Bender, David A.. Introduction to Nutrition and Metabolism. United Kingdom, Taylor & Francis, 2002.
• DePhillipo NN, Aman ZS, Kennedy MI, Begley JP, Moatshe G, LaPrade RF. Efficacy of Vitamin C Supplementation on Collagen Synthesis and Oxidative Stress After Musculoskeletal Injuries: A Systematic Review. Orthop J Sports Med. 2018 Oct 25;6(10):2325967118804544. doi: 10.1177/2325967118804544. PMID: 30386805; PMCID: PMC6204628.