5 Ways to Increase Your Vitamin C Levels
Vitamin C is made naturally in almost all living animals except humans, primates and guinea pigs. Dogs and cats produce their own vitamin C from ingested food that have metabolized into glucose. This mechanism keeps their vitamin C levels up without the need to consume vitamin C rich foods.
Humans must consume vitamin C from its food sources or they risk severe health problems. There is an intimate relationship between glucose and vitamin C that has a dramatic impact on immunity and overall cellular health. In this article, you will discover 5 keys to increasing your vitamin C levels.
Most animals and plants are able to synthesize their own vitamin C. This is done through a biochemical pathway that depends on 4 key enzymes which convert glucose to vitamin C. In mammals, the glucose is extracted from stored sugar (glycogen) and the transformation into vitamin C is produced in the liver (1, 2).
Glutathione Recycles Vitamin C
Humans lack the L-gulonolactone oxidase enzyme that is critical for the last step of vitamin C synthesis. Humans require a good amount of vitamin C in order to build healthy tissue collagen and promote strong immune function (3, 4).
When vitamin C levels are low the body makes due by recycling the oxidized version of vitamin C. This redox cycling is performed by the master anti-oxidant glutathione. As long as enough glutathione is present the vitamin C redox cycle can continue (5).
The Nobel prize winning chemist Linus Pauling discovered that white blood cells need very high doses of vitamin C in order to function effectively. In the late 1960’s, he developed the understanding of using high dose vitamin C to combat the common cold. This technique has worked effectively for many individuals; however, there is more to the story when it comes to vitamin C (6).
The GAA Theory
In the 1970’s, Dr. John Ely discovered the Glucose-Ascorbate-Antagonism (GAA) theory. Glucose and vitamin C (ascorbate) have a very similar chemical makeup. This theory proposes that elevated glucose levels compete and effectively restrict vitamin C from entering cells. Both glucose and vitamin C depend upon the pancreatic hormone insulin and its signaling effects in order to get into cells (7).
There is an important receptor called the Glut-1 receptor that activates in response to insulin to allow both glucose and vitamin C to enter the cell. However, glucose has a greater affinity for the insulin receptor. This means that the greater the content of circulating blood sugar the less vitamin C will enter the cell (8, 9).
White Blood Cells and Insulin Pumps
White blood cells have more insulin pumps than any other type of cell and may contain 20 times the amount of vitamin C as other cells. They also need 50 times more vitamin C inside the cell than in the blood plasma in order to handle the oxidative stress that occurs when they encounter a pathogenic substance (10, 11).
When white blood cells encounter pathogenic bacteria and viruses they must ingest or phagocytize these organisms in order to neutralize them. The phagocytic index measures how effective a particular white blood cell is at destroying viruses, bacteria & cancer cells. Elevated blood sugar impairs this phagocytic index. In fact, a blood sugar of 120 reduces the phagocytic index by 75% (12).
Vitamin C and the HMP Shunt
Glucose and ascorbic acid also work on the hexose monophosphate (HMP) shunt. The HMP is a biochemical pathway that produces NADPH. White blood cells need NADPH to create superoxide and other reactive oxygen species that oxidize and destroy pathogens (13).
Vitamin C not only helps produce NADPH but also regulates quantities so the white blood cell does not create too much oxidative stress in its attempt to protect the body.
Vitamin C activates this important shunt while glucose inhibits it. This HMP shunt also produces ribose and deoxyribose which provide important raw materials for the formation of new white blood cell RNA/DNA (14).
When the immune system is under attack it needs to quickly produce new immune cells. If blood sugar is high enough to turn off the HMP shunt it will reduce the quantity of RNA/DNA and the amount of new immune cells formed.
Best Food Sources of Vitamin C:
The current adult RDA for vitamin C is 60 mg, however, as a practicing clinician, I recommend my clients get at least 200 mg from food and ideally supplement with another 500mg -1 gram daily. In cases of chronic health conditions, I will recommend much higher dosages.
Here are the best food sources to consume to boost your vitamin C levels. Eating some of these on a daily basis is recommended. If you are doing a fast and not consuming food, I wouldn’t worry about it as your body will not have as great a need for vitamin C during the fast. But when you return to consuming food, be sure to include these vitamin C rich foods.
5 Ways to Increase Your Vitamin C Levels
Vitamin C is obviously extremely important for our overall health and there are 5 key things you can do to improve your levels.
Avoid sugar as much as possible and stick to a lower carbohydrate diet to improve your vitamin C levels. This includes processed sugars but also high starch foods such as potatoes, rice, high sugar fruits like bananas, watermelon, etc.
I recommend following a lower carbohydrate diet that is rich in non-starchy vegetables such as broccoli, cauliflower, kale, celery, asparagus, garlic, onions, mushrooms, cucumbers, etc. Consume grass-fed and organic animal products and lots of healthy fats from avocados, olives and olive oil and coconut oil. These foods will stabilize your blood sugar and insulin and improve your immune health.
Vitamin C Rich Foods:
Use low sugar whole food forms of vitamin C such as bell peppers, broccoli, lemon, lime, & green leafy veggies as much as possible to support your vitamin C levels. These foods sources should be included in most of your meals and you can also drink warm lemon water which not only provides vitamin C but is also a great support for healthy digestion.
You can also add in foods that are rich in quercetin which is a bioflavonoid that works in tandem with vitamin C to support the immune system. This would include onions, elderberries, cranberries, peppers and kale.
Use Vitamin C Supplements:
Vitamin C is an important component in controlling inflammatory responses to damaged tissues. Vitamin C also acts as an anti-histamine and helps to control hyperinflammatory responses to infections and allergies (15, 16, 17).
I recommend our Super C, which has a 1:1 ratio of vitamin C to citrus bioflavonoids which are also called Vitamin P. This combination of Vitamin C and Vitamin P synergizes to uniquely improve immunity, supports adrenal health and this synergy helps to improve capillary permeability to deliver more oxygen to cells. I personally use 1 gram (2 caps) in the morning upon rising and 1 gram at night before bed to support my adrenal health, circulation and immune system function.
Combining intermittent fasting with vitamin C supplementation and lemon water can be of great benefit for improving blood sugar regulation and immunity. Fasting will improve your blood sugar levels and take stress off of your digestive system, which frees up more energy for immune function, healing and repair.
Intermittent fasting is a strategy that involves fasting (not eating) for a period of time followed by a period of feasting (eating). Intermittent fasting increases autophagy, cellular rejuvenation, immune system function, and genetic repair. It reduces inflammation and the risk of disease. For more info on how to practice intermittent fasting, read this article.
Glutathione, commonly referred to as “the master antioxidant,” is a powerful force for our immune health. It helps to improve the inflammatory response and has the essential role of maintaining exogenous antioxidants such as vitamins C and E in their active form. Glutathione protects cells from free radicals and repairs free radical damage that does occur.
Many people are deficient in glutathione and may benefit from supplementation. For supplemental forms, look for reduced glutathione, acetylated glutathione and liposomal forms of glutathione. Additionally, precursers like N-Acetyl Cysteine (NAC) help the body to produce glutathione. Discuss dosages with your health care practitioner.
I have many of my clients boost their glutathione levels through natural strategies and key supplements such as Super Glutathione. Glutathione helps to recycle vitamin C and it may be more important as a supplement than vitamin C, although vitamin C can be of great benefit.
For optimal glutathione absorption and utilization within the cell, you want to use an acetylated form of glutathione that bypasses the gut and is easily absorbed into the cell. This is the form used in Super Glutathione. You can also use liposomal glutathione which also bypasses the gut and fuses into the cell membranes for optimal absorption.