Vitamin C: The missing link in bone health

Vitamin C: The missing link in bone health

When it comes to building healthy, strong bones, calcium and vitamin D seem to be the star nutrients. You may have also heard about the role of magnesium, vitamin D and vitamin K2 in bone health. But there is a very good chance that you are unfamiliar with how vitamin C may be an equally significant nutrient in this context.

We have a lot of evidence showing that you need vitamin C for the formation and maintenance of quality, high-density bones.

First, a quick rundown on bone formation and remodeling

You might think of your bones as an inactive organ, but the fact is there is a continuous action taking place in your bone cells and tissues.

The bone tissue is made up of minerals deposited around a protein matrix. Most of this protein matrix comprises of collagen – one of the most abundant proteins in your body. Collagen works as a glue that holds together our connective tissues present in the skin, muscle, ligaments, tendons, cartilage, bones, blood vessels and cornea of the eye. The collagen fibres provide the interior framework for bone minerals to deposit.

Your bone tissue, both the mineral part and protein matrix, is in a constant state of turnover. This means it is in the continuous cycle of being broken down and rebuilding, a process also known as remodelling. The primary aim of remodelling is to remove old and damaged bones, make new bones, help bones to adapt to changing mechanical stress and regulate levels of calcium and other minerals in the extracellular fluid.

Osteoblasts are the cells responsible for bone formation. These cells deposit calcium and phosphate into the bone matrix.

Osteoclasts are the cells responsible for breaking down the old bone. This process, also called resorption, releases calcium into the blood.

There is a continuous building and resorption of bones but the rate of these two processes is affected by age. For example, after age 35, the rate at which you are building new bones is slower than the rate at which you lose, leading to reduced bone mass as you age. That’s why people over 30 are generally prescribed calcium and vitamin D to halt the development of osteoporosis.

But again, we tend to overlook the importance of vitamin C here. Let’s look at how vitamin C fits so well in this entire ‘bone health’ equation.

Vitamin C is required for collagen formation

Osteoblasts, the cells that make new bones, make all kinds of proteins including collagen. As mentioned in the above section, all the bone mineral is laid down over a matrix that is predominantly made of collagen.

Healthy collagen serves as a strong support for bone mineralization – giving bones their strength, and resilience. Your body can’t make any collagen in the absence of vitamin C, which works as an important co-factor for the enzymes that are responsible for collagen biosynthesis. Vitamin C also helps in the synthesis of other non-collagenous proteins in the bone matrix.

Vitamin C exerts dual action on bone renewal

The skeleton undergoes constant renewal – building up and breaking down. This renewal or remodeling is important in maintaining healthy bones. A study released in 2010 found that vitamin C has a dual action on this process [1].

Stimulates the formation of osteoblasts, thus helping to build new bones
Supresses the formation of osteoclasts, thus helping in reducing bone resorption

Vitamin C fights oxidative stress in bone tissues

Vitamin C is a powerful anti-oxidant and limits the oxidative damage and resulting inflammation in bone tissues. Inflammatory reactions interfere with calcium assimilation into the bones while promoting bone resorption.

Vitamin C reduces hip fracture risk in post-menopausal women

Women tend to lose up to 20% of their bone density in few years after menopause. Decreasing levels of hormones, especially estrogen, interferes with the bone repair and renewal process and is linked to the loss of bone density over time.

Insufficient intake of vitamin C may increase the risk of osteoporosis. There is a lot of evidence suggesting that vitamin C supplements can be helpful in maintaining bone mineral density and in reducing the risk of fractures in older adults, especially among postmenopausal women. [2] [3] [4]

Speeds fracture healing

As a strong antioxidant and anti-inflammatory nutrient, vitamin C supplements are known to speed up the healing of fractures. Fracture healing is typically accompanied by a very painful process called complex regional pain syndrome (CRPS). Studies show that supplementation with vitamin C helps prevent this condition. [5]

Your body can’t make its own Vitamin C. Foods and supplements are your only source of getting this important nutrient. Since it is water soluble, excess is excreted out of the body in the urine. As such, there is no risk of vitamin C toxicity through taking quality supplements.

Don’t ignore magnesium and Vitamin K2

While most of us are aware that we need to take enough calcium and vitamin D (to help absorb calcium) to maintain healthy bones throughout our lives, supplements like magnesium and Vitamin K2 are often overlooked.

Calcium concentration in the body must be properly regulated. You don’t want too much calcium circulating in the bloodstream. Otherwise it can settle in soft tissues and organs including the bones, nerves, muscles, intestines and blood vessels. Too much calcium in these places can result in all sorts of health conditions – such as muscle cramps, kidney stones, arthritis and osteoporosis. It can even lead to plaque formation. This makes arteries hard and narrow, increasing the risk of high blood pressure, heart disease and stroke. This is where magnesium and vitamin K2 come into action.

Magnesium: You need vitamin D to absorb calcium. But did you know you need magnesium to convert vitamin D into a form that can be used by the body? Magnesium converts vitamin D into its active form called calcitriol. There are other ways magnesium helps in bone health:

Allows calcium to enter the cells when needed and steers it out when its job is done. This way magnesium keeps a check on calcium’s movement into and out of the cell. Insufficient magnesium makes it easy for the calcium to enter the cells without any restriction, which can lead to complications ranging from twitches, cramps and arrhythmia to osteoporosis, high blood pressure and heart disease.
Works along with thyroid and parathyroid glands to regulate calcium levels in the blood.

Vitamin K2: So, you get calcium from food or supplements. Vitamin D helps you absorb this calcium that you so need for healthy, strong bones. But calcium needs some help. It needs to be properly directed to the bones. This is where vitamin K2 helps. Vitamin K2 activates two important enzymes that bind to calcium and direct the mineral where it needs to be:

Activates Matrix Gla-protein or MGP. This enzyme binds to and remove the calcium present in the blood vessels.
Activates osteocalcin, protein released by osteoblasts, binds to the calcium circulating in the blood and helps it get to the bone matrix.

While you need a healthy balance of calcium, vitamin D and weight bearing exercises to maintain bone health and prevent significant bone loss in old age, vitamin C also plays an important role in preventing osteoporosis. In fact, vitamin C may work even better than bisphosphonates, a class of drugs, to treat osteoporosis. Studies show these drugs may actually cause weaker bones and increase risk of fractures in some individuals. On the other hand, Vitamin C improves bone mass, reduces risk of fractures in the elderly and accelerates fracture healing while slowing down associated pain and inflammation.

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