Few molecules are more abundant in healthy human cells or play a more important role in supporting bone and total body health than ascorbate (vitamin C).
When the Nobel laureate Albert Szent-Györgyi identified the long-sought-after molecule that prevented death from scurvy, he named it “ascorbic acid,” meaning without scurvy. This compound was found to be the same as the compound discovered earlier in the century, which Casimir Funk had called a “vitamine” because, like other trace factors in the diet, you die if you don’t consume it. He was studying diseases such as beriberi, pellagra, and scurvy for which small amounts of these “vitamines” cured the patient of the disease. “Vitamin C” was the curative factor for scurvy. However, since its identification in the early 1930s, decades of research have revealed that vitamin C is much more than a “vitamin.” This molecule is also our most abundant water-soluble anti-oxidant and a substrate essential for many vital physiological processes, including the development and maintenance of strong bones.
Well over 650,000 scholarly articles have been written on vitamin C and osteoporosis. Many of them report the essential role of vitamin C for the development and maintenance of our skeleton. Overall the studies on vitamin C and bone health look like the following (for details of these and other studies see Tables 1 and 2):
Higher vitamin C intake reduces risk of hip fracture
- The large, long-term Framingham Osteoporosis Study found that those with the highest vitamin C intakes had significantly lower risk of hip fracture.
- A large meta-analysis of 38 clinical studies document higher vitamin C intake is associated with lower hip fracture.
- A smaller meta-analysis of 6 clinical trials suggest that hip fractures were reduced 5% for every 50 mg increase in daily vitamin C.
Higher vitamin C intake is associated with greater bone density
- The same meta-analysis of 38 clinical studies mentioned above also found that greater vitamin C intake was associated with a 33% lower risk of osteoporosis.
- Another large study found vitamin C users had a bone mineral density approximately 3% higher than nonusers.
- A 2003 cross-sectional study found higher dietary vitamin C was associated with greater hip bone mineral density.
The Terms “Vitamin C” and “Ascorbate”
As we begin to understand the role of ascorbate or vitamin C in bone health, let me explain my use of the word “ascorbate.” Several metabolites (forms) of vitamin C (also called ascorbic acid) exist. The ascorbic acid metabolite found and used in the body is the “ascorbate” form. Thus, I use the term “ascorbate” when I discuss the physiological functions of vitamin C within the human body.
Ascorbate is a major electron donor, making it a powerful anti-oxidant. Ascorbate can be “fully reduced” which means that it has all its electrons in place, making it an even more powerful anti-oxidant. Ascorbate can also be partially oxidized (exposed to light & air), thus making it a less potent anti-oxidant; that is, making it less capable of protecting all cells from free radical damage. Ascorbate can also be “fully buffered,” which means it is attached to selected minerals in a balanced fashion. These minerals help with the uptake and utilization of the ascorbate. A fully buffered ascorbate helps reduce unwanted metabolic acids while serving as an anti-oxidant (i.e., it alkalizes).
Here at the Center for Better Bones we supplement with a potent, fully buffered, fully reduced ascorbate called Alkalini-C.
Whole Body Protection of Ascorbate/Vitamin C
The 90+ years of research on ascorbic acid (vitamin C) reveal that ascorbate possesses a multitude of properties and plays myriad roles within the human body. The following illustration details what I find to be the most important functions of vitamin C. As you can see, this is indeed an impressive list of actions.
The Multiple Actions of Ascorbate/Vitamin C
© Susan E. Brown, PhD 2020
Ascorbate (Vitamin C) and Bone
Many of the actions of ascorbate illustrated above explain exactly how vitamin C impacts and works directly to strengthen bone.
Let’s look at the top 6 specific bone-strengthening actions of ascorbate/vitamin C.
1. Ascorbate is essential for production of healthy collagen.
One third of bone is collagen and ascorbate (vitamin C) is essential for the production of healthy collagen. Collagen forms the living protein matrix of bone that gives bone its strength and flexibility. Without healthy collagen, bone loss is excessive and bones will weaken.
A vitamin C deficiency “inhibits the transcription of various types of collagen found in skin, blood vessels, and tissue.” The impact of this is that bone formation is altered and bones become brittle.
Scurvy, the life-threatening disease caused by vitamin C deficiency is a collagen-deficit disorder. The key feature of scurvy, hemorrhage, can occur in almost any organ and ample ascorbate/vitamin C can build collagen and prevent scurvy.
2. Ascorbate is the most abundant water-soluble anti-oxidant that protects bone.
Not only is ascorbate/vitamin C a predominant anti-oxidant, but it also serves to regenerate two other key anti-oxidants, glutathione and vitamin E. For this reason, ascorbate/vitamin C has been dubbed the “maternal sacrificial antioxidant.” Like a loving mother, ascorbate gives of itself to regenerate other essential anti-oxidants.
3. Ascorbate directly impacts bone cells to favor the development of strong bones.
Ascorbate directly enhances the development and action of the bone-building osteoblast cells while decreasing the activity of the bone-breakdown osteoclast cells. These bone-building benefits accrue from ascorbate’s roles as an anti-oxidant and pro-collagen factor.
4. Ascorbate is a potent anti-inflammatory agent.
Ascorbate reduces the negative effects of unwanted chronic inflammation in various ways. One way is by decreasing the production of immune system pro-inflammatory compounds such as cytokines, which tend to break down bone.
5. Ascorbate serves as a substrate for the biosynthesis of many key compounds.
Ascorbate is essential for the biosynthesis of l-carnitine and several neurotransmitters (such as norepinephrine) and adrenal steroid hormones. Adrenal health is central to our stress response and to bone health. And the adrenal gland is one of the organs with the highest concentration of vitamin C.
Carnitine is an amino acid that plays a critical role in cellular energy production, transporting long–chain fatty acids to the energy power plant of all cells, the mitochondria. Carnitine has also been shown to reduce bone loss in animal and human studies and to assist in fracture healing.
6. Ascorbate helps detoxify bone-damaging heavy metals.
Lead, cadmium, mercury, and other toxic metals directly impact bone. Ascorbate/vitamin C helps to detoxify various heavy metals. My mentor, Dr. Russell Jaffe MD, PhD reports that 2,000 mg of buffered ascorbate are needed every day just to detoxify the new amount of heavy metals we take in from food, water, air, and direct contact.
How Much Ascorbate/Vitamin C Do You Need to Optimize Bone Health?
The US RDA (recommended dietary allowance) for vitamin C is 60 mg/day for women and 90 mg/day for men. This is plenty enough to prevent scurvy, the fatal outcome of vitamin C deficiency. However, the optimal level of ascorbate/vitamin C needed by any individual is much higher and is not uniform. Some individuals need much more than others depending on the degree of immune challenge (the amount of burden on one’s immune system), toxic burden, and overall anti-oxidant need.
Furthermore, unlike all plants and most animals that produce their own vitamin C, humans, monkeys, and apes are among the few animals that cannot synthesize their own vitamin C. As Nobel laureate Linus Pauling and others have pointed out, apes consume from 2,000 to 4,000 mg of vitamin C per day from their diet. This finding suggests that 2,000 mg to 4,000 mg of vitamin C per day might be a healthy starting point for healthy humans.
Keep in mind that any sort of immune challenge, whether it be from a virus, from pollutants and toxic exposure, infections, or disease, will increase one’s need for ascorbate/vitamin C. Here at the Center for Better Bones we generally begin our clients on 2,000 to 4,000 mg/day of fully reduced, fully buffered ascorbate and increase or decrease as appropriate.
Table 1 Vitamin C and Hip Fracture Studies
|15- to 17-year follow-up of the Framingham Osteoporosis Study||958 adult men and women (mean age 75). Participants were divided into three groups based on vitamin C intake.||The group with the highest vitamin C intake had a significantly lower risk of hip fracture as compared to those in the lowest tertile. They had the fewest hip fractures and lower risk of all non-vertebral fractures compared to the group with the lowest intake.||https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2766028/ |
|38 clinical studies |
|Greater vitamin C intake was associated with lower risk of hip fracture and osteoporosis, as well as higher BMD at femoral neck and lumbar spine. |
|Meta-Analysis||6 clinical studies||Greater vitamin C intake reduced hip fracture risk. Specifically, 50 mg/day reduces hip fracture by 5%.|| |
|Case-Control Study||167 cases||Subjects in the highest vitamin C quartile had reduced risk of fractures compared to those in the lowest quartile.||https://econtent.hogrefe.com/doi/abs/10.1024/0300-98188.8.131.529 |
Table 2 Vitamin C and Bone Density Studies
|Meta-Analysis||38 clinical studies||Greater vitamin C intake was associated with a 33% lower risk of osteoporosis.||https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/vitamin-c-intake-in-relation-to-bone-mineral-density-and-risk-of-hip-fracture-and-osteoporosis-a-systematic-review-and-metaanalysis-of-observational-studies/E1229B088231CD96AE676352030F428B |
|Observational study||994 post-menopausal women (mean age 72), 277 of whom were regular supplement users||Vitamin C users had bone mineral density levels approximately 3% higher at the midshaft radius, femoral neck, and total hip. Women taking both estrogen and vitamin C had significantly higher bone mineral density levels at all sites.||https://asbmr.onlinelibrary.wiley.com/doi/full/10.1359/jbmr.2001.16.1.135 |
|Observational Study |
|136 post-menopausal women |
|High dietary vitamin C intake was associated with greater bone mineral density of total femur, trochanter, Ward’s triangle and shaft |
|Observational Study||1,892 post-menopausal women||Longer vitamin C supplement use was associated with higher hip bone density in women who never used estrogen and were in the age group 55-64||https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1060531/pdf/jepicomh00179-0011.pdf |