By Doreen, Pharmacist
Vitamin C is a popular supplement. There are several forms of vitamin C available. Naturally you may wonder which vitamin C is best absorbed or has the best bioavailability?
Bioavailability refers to the degree to which a nutrient becomes available to the target tissue after it has been administered.
Does Vitamin C Type Affect Bioavailability?
Vitamin C is also known as ascorbic acid, which is the form used in most supplements. However, there are other forms of vitamin C, including, sodium ascorbate (a mineral ascorbate), calcium ascorbate (a mineral ascorbate), other mineral ascorbates, ascorbic acid with bioflavonoids or combination products that blend different forms.
Regardless of the form of vitamin C, their bioavailability is very similar. Although some singular studies show minor differences, the body of research surrounding vitamin C supplementation reflects that absorption remains high no matter which form you choose.
Synthetic vs. Natural Ascorbic Acid
Ascorbic acid occurs naturally in many fruits and vegetables. Synthetic and natural ascorbic acid are chemically identical. There are no known differences in the bioavailability of vitamin C.
However, some people find that vitamin C given in the supplemental form of ascorbic acid upsets their stomach.
Very High Doses ≠ More Bioavailable Ascorbic Acid
The bioavailability is high when we supplementing vitamin C at the normal recommended intake (85–90 mg per day). However, the body carefully controls the amount of ascorbic acid circulating in your system throughout the day, excreting any excess. Therefore ingesting 1,000 mg or more a day does not equate to more bioavailable ascorbic acid in the body.
Mineral ascorbates such as calcium and magnesium ascorbate are often called ‘buffered’ vitamin C. Mineral salts (mineral ascorbates) are less acidic, so it is gentler and better tolerated by the gut.
One quick note about mineral ascorbates: remember that if you opt for these forms, you are getting more than just vitamin C. Always check labels to see how much vitamin C/ascorbic acid and how much of other minerals are in each dose so you can factor that into your overall supplementation
Bioflavonoids (or flavonoids) are polyphenolic compounds found in plants. Vitamin C-rich fruit and vegetables, especially citrus fruit, are often rich sources of flavonoids as well. There are around 5,000 different varieties of flavonoids and they are made by plants in response to microbial infection. Some research has found that the addition of flavonoids may help to increase the absorption of vitamin C from supplements; other studies however have found there to be no difference.
PureWay-C® is a unique and advanced form of vitamin C. PureWay-C® contains fatty acids, which allow ascorbic acid to enter cells more quickly in a safe and effective manner, acting as ascorbic acid carriers to increase intestinal absorption and tissues distribution of vitamin C and enhance cellular uptake.
A 2007 study demonstrated that PureWay-C® is more rapidly absorbed and more highly retained (233% higher) by the human body than all forms of Vitamin C tested for all time points.5
PureWay-C® is also not associated with any adverse effects typically associated with mega doses of vitamin C. Compared with others, PureWay-C® seem to be absorbed better in many instances, which means they can bring up vitamin C levels to normal and healthy levels even when taken in small amounts.
- 6 of the best vitamin C supplements: What to look for (medicalnewstoday.com) retrieved from https://www.medicalnewstoday.com/articles/best-vitamin-c-supplements#what-to-look-for
- Nutri Advanced | Confused About The Different Types of Vitamin C? | Nutri Advanced retrieved from https://www.nutriadvanced.co.uk/news/confused-about-the-different-types-of-vitamin-c/
- PQ_BioavailabilityDifferentFormsVitaminC_4.17.2015.pdf (perque.com) retrieved from https://www.perque.com/wp-content/uploads/2018/02/PQ_BioavailabilityDifferentFormsVitaminC_4.17.2015.pdf
- Vitamin C-lipid metabolites: uptake and retention and effect on plasma C-reactive protein and oxidized LDL levels in healthy volunteers - PubMed (nih.gov) retrieved from https://pubmed.ncbi.nlm.nih.gov/18971870/
- Absorption rates and free radical scavenging values of vitamin C-lipid metabolites in human lymphoblastic cells - PubMed (nih.gov) retrieved from https://pubmed.ncbi.nlm.nih.gov/17901843/