Vitamin C Rich Diet
by Sue Kira, Naturopath & Clinical Nutritionist
Recommended daily allowance of vitamin C
Rich food sources of vitamin C
About Vitamin C
Did you hear about sailors in the 15th to 18th centuries who roamed the world, yet many died from scurvy due to inadequate supplies of vitamin C rich foods like fruits and vegetables? Fortunately, the menus on today’s massive ships are somewhat more sophisticated and loaded with vitamin C rich foods…but it still means you must eat them to avoid vitamin C deficiency.
Vitamin C, also known as ascorbic acid (among other names) is a water-soluble vitamin that is very sensitive to heat, light, and air, so it’s easily oxidized and made ineffective. It’s the least stable of all the vitamins in this way, so it is best obtained and eaten fresh and raw.
The primary role of vitamin C is to maintain collagen levels, a protein necessary for the formation of connective tissue in skin, ligaments, and bones. Vitamin C plays a role in the formation of red blood cells and the prevention of haemorrhage. It is frequently used to help support the common cold as it helps to fight bacterial infections.
Vitamin C has a strong relationship with other nutrients in a supportive way as it helps with the metabolism of amino acids phenylalanine and tyrosine, helps folic acid convert to folinic acid (the more active form) and may play a role in calcium metabolism.
Additionally, vitamin C protects thiamine (B1), riboflavin (B2), pantothenic acid (B5), folic acid (B9), and vitamin A and E against oxidation.
Vitamin C is essential for the formation of adrenaline and during times of stress, large amounts of vitamin C, stored in the adrenal glands, are rapidly used up, which then lowers the body’s resistance to stress and infection.
Ever noticed when you get run down you can get sick more easily?
Vitamin C can also be useful to aid iron absorption, which is great if you tend to get low iron. However, if you have high iron, iron overload, or haemachromatosis, then avoid eating vitamin C rich foods with a meal containing iron, like meat.
Even though some vitamin C can be stored in the adrenals, most vitamin C that is in the blood will be excreted within 2-3hrs so it is better to either eat foods with vitamin C regularly, or have small doses of vitamin C often throughout the day, particularly if using it to support an infection. Higher doses of vitamin C are needed during stress, infection, and healing connective tissue damage.
Men, apes, and guinea pigs are among the very few that cannot make their own vitamin C and therefore must obtain it from their diet or supplements.
Diet, stress, petrochemical fumes, high fever, antibiotic use, Asprin, cortisone, painkillers and smoking reduce the body’s ability to absorb vitamin C. Sulphur drugs can increase the excretion of vitamin C, as can drinking excessive amounts of water.
The use of baking soda and antacids creates an alkaline environment in the stomach that destroys vitamin C. Copper cookware can destroy vitamin C content of foods. If someone has a high copper level they need more vitamin C; this can happen when using the contraceptive pill as it elevates copper levels. Vitamin C can also help to clear lead from the body.
Those on a high protein diet, or who have hypoglycaemia, will need more vitamin C as these situations interfere with vitamin C metabolism. People with acid conditions, or are prone to kidney stones, are advised to use sodium ascorbate for vitamin C intake, rather than the ascorbic acid form, otherwise stone formation risk can increase.
Signs of a deficiency of vitamin C are impaired digestion, poor lactation, shortness of breath, swollen or painful joints, nosebleeds, anaemia (as vitamin C helps iron absorption), slow healing of wounds or fractures, tendency to bruise easily, bleeding gums, broken capillaries, blood clots, and in severe deficiency, scurvy.
Rich sources of Vitamin C can be found in citrus fruits, rose hips, acerola cherries, alfalfa sprouts, cantaloupe/rockmelon, strawberries, tomatoes, and capsicums/bell peppers and most other fruits and vegetables.
Benefits of vitamin C
Healthy immune system
Vitamin C has long been known as the vitamin that helps to support our immune system. It does this by reducing an inflammatory compound called histamine.
Vitamin C is also a powerful antioxidant that protects our cells from the damage of infection and inflammation. Vitamin C also increases blood flow to enable our white blood cells to get to the source of infection quicker and help our immune system fight off bacteria and viruses. Vitamin C can also help with faster wound healing for the same reason.
The anti-histamine effect can lessen the symptoms of a flu or cold such as runny nose, aches and pains and watery eyes.
Because vitamin C can reduce the effects of histamine and inflammation, people with asthma can feel better with more vitamin C in their diet or with supplemental doses of vitamin C.
The antioxidant properties of vitamin C can help protect our cells from DNA damage and mutation which may help protect us from cancer. Vitamin C does not attack cancer cells, but it keeps the immune system nourished for it to be able to better destroy any cancerous cells.
Healthy vascular system
Vitamin C is so amazing as an antioxidant that it can help to prevent plaque formation in our arteries by preventing cholesterol from oxidising, which is the main reason for the build-up in arteries in the first place. It is definitely not good for you to eat the rancid fats, hydrogenated fats and sugars that create the oxidisation in the first place.
Because of vitamins C’s role to keep blood flowing well, it can also help to keep our blood pressure normal. All these factors make vitamin C helpful in the prevention of heart attacks, stroke and other vascular disorders.
Healthy stress response
We all have stress from time to time, some we would rather do without. But other stress is self-imposed by overdoing exercise and other activities that put stress on the body. That’s why I have seen athletes, particularly endurance athletes, succumb more easily to illnesses because the load on their body drains valuable nutrients, such as vitamin C.
No matter how you look at it, all stress, whether emotional, physical, or psychological, needs the support of good nutrients including vitamin C (plus magnesium and B vitamins) not to mention looking at how to deal with and avoid negative stress where possible.
Stress increases certain hormones like cortisol and adrenalin, both of which can be supported with plenty of vitamin C. Vitamin C is considered the most valuable adrenal vitamin (our adrenals produce the stress hormones).
Healthy eyes
A bonus for consuming plenty of vitamin C is that it can help to increase blood flow to the eyes and improve vision. As a powerful antioxidant it can also help to prevent cataracts and even slow down the effects of existing cataracts.
Diabetes support
Vitamin C can help to regulate glucose in diabetes by helping glucose get into the cells easier instead of building up in the blood. The vascular support of vitamin C helps to increase blood flow in the body. This can help prevent some of the complications of diabetes like poor blood flow to the extremities, kidneys, and eyes that can lead to blindness, kidney failure and the risk of amputation.
Healthy skin
Vitamin C helps our bodies to make hydroxyproline and hydroxylysine, needed to make collagen, a very important molecule that keeps our skin youthful, plump, elastic and hydrated. Collagen not only keeps our skin looking good, but it also is needed for the structure of our blood vessels.
The tiny capillaries and veins under our skin carry oxygen and need the support of collagen to support their structure. Without collagen, the structure is compromised which leads to broken vessels (the tiny red lines under the skin) and varicose veins.
As an antioxidant, vitamin C also helps to protect our skin from the damaging effects of ultraviolet radiation from the sun and environmental toxins. Some companies use vitamin C in their skin care blends for this reason. Vitamin C can also help to lighten skin discolorations like freckles and age spots and helps to maintain smooth skin. Wounds also heal much faster with adequate levels of vitamin C.
Healthy hair
Vitamin C is said to help prevent baldness and premature hair greying. This would be the case if the hair loss and greying was due to stress, as adrenal hormones (cortisol and adrenaline) need a lot of vitamin C to combat stress. With low levels of vitamin C, we stress more and have additional oxidative stress, which can contribute to making hair weak, thin, and brittle.
Vitamin C can also inhibit the bacteria that can grow on the skin of our scalp that can lead to dandruff. The anti-viral and anti-inflammatory effects of vitamin C also help to prevent dry itchy scalp. For thick strong hair, we need good blood circulation which vitamin C supports.
Vitamin C deficiency symptoms
- Fatigue
- Muscle weakness & muscle aches
- Joint aches
- Leg rashes
- Dry and splitting hair
- Rough, dry, and scaly skin
- Gingivitis or inflammation of gums, or bleeding gums
- Slow wound healing
- Easy bruising & nosebleeds
- Getting sick more easily (we need vitamin C for a healthy immune system)
Severe vitamin C deficiency is called scurvy. Scurvy creates liver spots on the skin, spongy gums, open sores, and bleeding in many places (gums, eyes and nose). A person with scurvy looks pale, depressed, and can become immobilised. Advanced scurvy can lead to death.
Fortunately, most people who eat some fruit or vegetables don’t get scurvy. This condition is usually limited to third world countries where people are starving. The early explorers who travelled by ship didn’t know that they could prevent scurvy by eating the berries on bushes like the indigenous populations did.
Even without the extremes of scurvy, low levels of vitamin C can lead to problems such as hypertension (high blood pressure), cancer, issues with the gallbladder, tooth loss and atherosclerosis, which is the build-up of plaque that can lead to stroke and heart attack.
It makes sense to get adequate amounts of vitamin C from your diet.
Side effects of too much vitamin C
It is virtually impossible to get too much vitamin C from foods alone, but with supplements, the recommended dose on the bottle should normally not cause any problems, provided your doctor or health practitioner says it’s fine to take it alongside any treatment you are being prescribed.
However, if you take more than the recommended dose, or have been recommended a high dosage, then you may get transient effects such as diarrhea, abdominal cramps, excessive urination, pain in the kidneys (lower back and flank areas) and nausea. Some may call this your bowel tolerance level, where you get to the point of diarrhea and then reduce the dosage until those symptoms cease. Alternatively, start slowly and gradually increase until you reach your bowel tolerance level.
Vitamin C can interact with certain medications such as anticoagulants like Warfarin (Coumadin) because vitamin C can also thin the blood. You don’t want your blood too thin and watery or you can get bleeds under the skin, or worse still, internal bleeding.
In rare cases, excess vitamin C has caused kidney stones for some.
Medications such as the ‘pill’, hormone replacement therapies, antibiotics such as tetracyclines, and nicotine from smoking or patches, can all decrease your levels of vitamin C.
Generally, your body can only hold around 2000mg of vitamin C at a time, usually for around two hours, and the excess is passed out via urine. If you are sick or under a lot of stress, including the oxidative stress of smoking, your body may use more vitamin C at any given time.
For example, when we have a cold, we could take 2,000mg every two hours and not get diarrhoea – but if we did that when we are well we would surely be running to the toilet.
As mentioned, lots of stress uses up lots of vitamin C, which is why we often get sick much easier when we are ‘run down’ from stress or overworking. There was a study I read many years ago about vitamin C and stress. Unfortunately I can’t find the source, so please don’t quote me on these numbers as they may not be accurate, but it will give you an idea of the amount of extra vitamin C we need during times of stress.
The study was done on goats. Goats, unlike us, make their own vitamin C like a lot of other animals do. The researchers first measured the amount of vitamin C that goats produced on a relaxed day out in the paddock, chewing grass and having a delightful time. Then they put these poor goats under stress and remeasured their output of vitamin C.
The level varied from 100mg per day unstressed, up to 100,000mg per day when stressed. Now while I don’t know what their actual stressors were, I do remember that the amount of vitamin C they produced when stressed was astronomically higher than when not stressed.
When we’re stressed, we don’t think, ‘Oh, I better take some more vitamin C to compensate’. And this is one theory why stress can contribute to all sorts of diseases, including cancer.
Recommended daily allowance (RDA) of vitamin C
Following is the recommended daily allowance (RDA) for vitamin C. The amounts are expressed in milligrams. A milligram = 1,000th of a gram. This list is really the minimum amount needed to survive and not get scurvy. Personally, I feel the level needs to be much higher, especially if you have any stress in your life. Most Vitamin C supplements are around 500-1000mg per dose.
- 0-6mths: need 40mg
- 7-12mths: need 50mg
- 1-3yrs: need 15mg
- 4-8yrs: need 25mg
- 9-13yrs: need 45mg
- 14-18yrs boys: need 75mg
- 14-18yrs girls: need 65mg
- Men: need 90mg
- Women: need 75mg
- Pregnant women: need 85mg
- Breastfeeding women: need 120mg
- Smokers: need 250mg minimum
Rich food sources of vitamin C
Following are some foods rich in vitamin C, showing the weight of the food and the quantity of vitamin C in milligrams. This list of foods can be used in conjunction with the above RDA’s. You can see that it is relatively easy to maintain the daily recommended levels of vitamin C from food.
- Apples (diced): 1 cup = 5.8mg
- Avocado (medium): 1 = 20mg
- Bananas (medium): 1 = 10mg
- Red bell peppers/capsicum: 1 = 340mg
- Broccoli raw (chopped): 1 cup = 80mg
- Coconut: 1 cup = 3mg
- Cranberries: 1 cup = 13mg
- Figs: 1 cup = 3mg
- Grapes: 1 cup = 4mg
- Kale (chopped): 1 cup = 80mg
- Kiwifruit: 1 = 65mg
- Lemons: 1 = 30mg
- Lychee (without skin and seed): 1 = 7mg
- Oranges (medium): 1 = 70mg
- Papaya (cubed): 1 cup = 88mg
- Passionfruit (pulp): 1 cup = 70mg
- Pear (medium): 1 = 8mg
- Persimmon: 1 = 16mg
- Pineapple (chopped): 1 cup = 80mg
- Pomegranate: 1 = 28mg
- Strawberries (sliced): 1 cup = 98mg
- Tomatoes: 1 cup = 55mg
- Watermelon: 1 cup = 12mg
Important:
Before you commence your diet, see your medical or health care professional for qualified guidance about what foods and supplements are best for your body. While on the diet do not stop any medications or supplements previously prescribed unless advised otherwise by your medical or health care professional.
During the early stages of a new diet, you may experience symptoms such as fatigue, headaches, or body aches, which may occur because your body is detoxifying. However, if you are unsure about a symptom at any time, check immediately with your medical or health care professional.