Vitamin C is a water-soluble vitamin that is known for its immune-boosting properties. However, this nutrient has powers extending far beyond this!
Roles of Vitamin C in the Body
- The body needs vitamin C to synthesise collagen and elastin and other critical elements in our bone matrix, skin, tooth dentin, gums, blood vessels, and tendons.
- The body requires vitamin C to utilise other nutrients like B vitamins.
- Vitamin C is infamously known as an antioxidant. In this sense, it helps to protect against cellular damage from free radicals.
- Our immune system requires vitamin C to protect against infections. Vitamin C is antiviral, antifungal, and antibacterial, and it helps reduce the severity of allergic reactions.
- Vitamin C is known for its detoxifying properties.
- Blood sugar regulation and glucose control require vitamin C.
- We require vitamin C to convert cholesterol into bile acids. Bile acids are produced by the body to process toxins and break down dietary fats.
- Vitamin C is protective against various conditions, like cardiovascular diseases, cancers, joint disorders, cataracts, and even the common cold.
Many plant and animal species can synthesise their own vitamin C. However, humans and certain mammals lack this ability. For this reason, vitamin C is an essential nutrient for humans because we can’t make our own. It is thought that humans lost the ability to make Vitamin C because it was so plentiful in our native diets during the time we evolved.
- Roles of Vitamin C in the Body
- What Happens if Your Vitamin C Intake is Too Low?
- Vitamin C Supports Neurotransmitter Synthesis
- What Foods Contain the Most Vitamin C?
- Recipes to Boost Your Vitamin C
- History of Vitamin C
- Conditions that Increase Your Demand for Vitamin C
- Preserving Vitamin C
- Satiety Response to Foods with More Vitamin C
- Vitamin C Side Effects, Toxicity, and Overdose
- Optimal Vitamin C Intake
- Availability of Vitamin C in the Food System
- Is There Any Vitamin C in Meat?
- Nutrient Profile of Foods High in Vitamin C
- How Do I Calculate My Vitamin C Intake?
- Nutrient Density Index
What Happens if Your Vitamin C Intake is Too Low?
Vitamin C is helpful for a variety of chronic health issues, including:
- high blood pressure,
- heart disease,
- macular degeneration,
- diabetes or prediabetes,
- Ehler’s Danlos Syndrome (EDS),
- connective tissue disorders,
- high cholesterol,
- heavy metal toxicity,
- adrenal imbalances,
- Inflammatory conditions,
- chronic fatigue syndrome (CFS),
- elevated uric acid levels and gout,
- poor iron absorption,
- weak immunity, and
- poor memory.
Vitamin C Supports Neurotransmitter Synthesis
Neurotransmitters are chemicals produced by the body that trigger emotions, initiate movement, and initiate reactions. Vitamin C is critical to help you make neurotransmitters like dopamine, noradrenaline, and acetylcholine that:
- stop you from peeing at night,
- prevent you from overeating,
- make you happy,
- improve your focus and motivation,
- increase your sex drive,
- stop your hair from going grey, and
- boost your thyroid, adrenal and sex hormones.
What Foods Contain the Most Vitamin C?
Vitamin C is found in plant foods. It is primarily concentrated in greens, citrus, and brightly coloured produce. For this reason, it is not a nutrient of concern for someone on a plant-based diet if they’re consuming nutrient-dense foods.
- green peppers
- lemon juice
- lime juice
- sweet potato
Recipes to Boost Your Vitamin C
Some examples of our NutriBooster recipes high in Vitamin C include:
- red cabbage & parsley salad
- arugula, bell pepper & mushroom salad (pictured below)
- cruciferous juice
- mashed cauliflower
- quinoa stuffed peppers
Since the 1500s, we have known that fresh fruits and vegetables could prevent scurvy, or a condition that results from low vitamin C. Scurvy was a common killer of sailors on long voyages because of their inability to consume fresh produce. As a result, sailors consumed sauerkraut, which contains adequate amounts of vitamin C, to stave off deficiency.
James Lind undertook the first documented, controlled trial to establish that citrus fruits prevented scurvy. Subsequently, Vitamin C was the first vitamin to be discovered in 1912. It was later isolated in 1928 and synthesised in 1933.
Because fresh produce is more readily available in the modern food environment, Vitamin C deficiency (scurvy) is rare today. However, you may still be at a higher risk of Vitamin C deficiency if you:
- are not able to eat fresh or minimally processed foods (e.g., the elderly, low-income households, or someone suffering from an eating disorder),
- are exposed to large amounts of toxins (e.g., have heavy metal toxicity, are recovering from mould exposure, have a chronic infection like Lyme),
- use a lot of Advil, aspirin, or other NSAID pain relievers,
- are undergoing chemotherapy for cancer treatment,
- suffer from conditions like autoimmunity or cancer resulting from compromised immunity,
- are dependent on cigarettes, alcohol, or drugs, or
- have a health condition like coeliac disease, irritable bowel syndrome (IBS), ulcerative colitis or Crohn’s disease that inhibits the absorption of nutrients.
Vitamin C is a water-soluble nutrient that is sensitive to alkalinity, heat, and light. It remains stable in dry powder form, but it is highly unstable and degrades in food if it is mishandled. Losses during processing can range from 10 to 90%. Hence, it’s critical to focus on fresh food and avoid overcooking foods rich in vitamin C.
Our satiety analysis of Nutrient Optimiser users shows only a moderate satiety response to foods containing higher levels of Vitamin C.
People who consume more Vitamin C from their diet tend to consume around 14% fewer calories.
The Estimated Average Requirement (EAR) for Vitamin C is set at 30 mg per day with a Recommended Daily Intake (RDI) of 45 mg per day.
This amount is just enough to counter deficiency and isn’t necessarily optimal. In contrast, the average consumption of Optimisers is much higher at 200 mg per day.
We do not see a greater satiety response from supplemental vitamin C. In fact, amounts of vitamin C that are only achievable from supplementation tend to align with a higher calorie intake.
So, while vitamin C supplements may be beneficial if you have a deficiency, supplementing vitamin C will not improve the satiety value of an otherwise nutrient-poor low satiety diet.
While many people recommend high doses of Vitamin C for general health, the Upper Limit (UL) of Vitamin C is set at 2000 mg/day to account for gut tolerance. Too much supplemental vitamin C has a laxative effect and will send you running to the toilet!
While an upper limit has been set for vitamin C, no known dose causes toxicity or overdose unless someone has a pre-existing condition. Because vitamin C is water-soluble, excess amounts are excreted. The body is also capable of absorbing only so much through the intestinal tract.
Because of vitamin C’s relationship with other nutrients, chronic high Vitamin C supplementation can lead to excess iron absorption (iron overload), which increases oxidative stress, Vitamin B12 deficiency, and erosion of dental enamel.
Optimal Vitamin C Intake
Based on the satiety response, a reasonable vitamin C stretch target of 350 mg/day for men and 280 mg/day for men is recommended from food.
|Vitamin C (mg)||350||280|
Vitamin C availability has varied over time. Today, a significant amount of Vitamin C is used as an additive in food to prevent browning. Based on USDA data, there may have been an increase in Vitamin C fortification around 1970.
It is reasonably easy to get adequate vitamin C to meet the EAR and RDI from our modern food system. However, you will need to go out of your way to focus on more nutrient-dense foods and meals if you want to achieve more optimal levels.
Your absorption of Vitamin C depends on how much you’re getting through diet. If you consume high amounts of supplementation, your body will likely downregulate absorption of Vitamin C. In contrast, your body will absorb more vitamin C if the demand is high. This is because your intestines regulate absorption based on body requirements.
Approximately 70%–90% of Vitamin C is absorbed in moderate intakes of 30–180 mg/day. However, absorption falls to less than 50% at doses above 1.0 g/day. Unmetabolized Vitamin C is excreted in the urine.
It’s also worth noting that adequate Vitamin C is required to absorb non-heme iron successfully.
Is There Any Vitamin C in Meat?
Glucose and Vitamin C have similar chemical structures and compete for the same transporters in the cell membrane. Both are escorted into the cells by the action of the hormone insulin. Thus, high glucose levels in your diet mean you will require more insulin and more Vitamin C to get glucose into the cell. Based on this logic, it appears that a diet with less glucose may require less Vitamin C.
Liver and organ meats contain some Vitamin C. However, other meats are typically assumed to have no Vitamin C, and their content is typically is not measured. Fresh meat and fish contain some, although much is lost during cooking. While people consuming lots of fresh meat do not appear to develop scurvy, there are anecdotal reports of people following a strict carnivore diet developing symptoms of scurvy.
The minimum required intake of Vitamin C to prevent deficiency is reasonably easy to obtain from eating fresh food on an omnivorous diet. However, if your diet has minimal glucose, your minimum requirement for Vitamin C may be even lower.
It is unknown whether the lower intake of Vitamin C on a carnivorous diet would affect iron absorption, given that iron availability would be high.
The nutrient fingerprint below shows that it is easy to obtain the minimum required intake of Vitamin C. Foods high in vitamin C tend to be lower in fat, with plenty of naturally occurring fibre.
Because foods rich in vitamin C are predominantly plant-based, at the top of the micronutrient fingerprint chart, we see that we can miss out on nutrients like B12, retinol, methionine, omega-3, and selenium found readily in animal foods if we only focus on foods high in Vitamin C.
How Do I Calculate My Vitamin C Intake?
If you’re interested in checking if you’re getting enough vitamin C in your diet, you can check your nutrient profile using our Free 7-Day Nutrient Clarity Challenge.
Level Up Your Nutrient Density
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- Maximum Nutrient Density Food List
- Sample Maximum Nutrient Density Recipe Book
- Sample Maximum Nutrient Density Meal Plan.
To get started today, all you have to do is join our new Optimising Nutrition Group here.
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Nutrient Density Index
- Vitamin A
- Vitamin E
- Thiamine (B1)
- Riboflavin (B2)
- Niacin (B3)
- Pantothenic acid (B5)
- Vitamin B6
- Folate (B9)
- Vitamin B12
- Vitamin C
- Vitamin D
- Vitamin K1