A recent animal study suggests that vitamin D may provide a treatment and prevention method for degenerative changes of the intervertebral disc among diabetic patients.
Intervertebral discs act as cushions between each of the small bones forming the backbone, known as the vertebrae.
Natural daily stresses, minor injuries and aging cause spinal discs to gradually breakdown. This is known as disc degeneration. Over 30% of people between the ages of 30 and 50 years old are estimated to be effected by disc degeneration.
As the intervertebral discs weaken, they begin to collapse. This results in pressure on the nerves in the spine, which can be quite painful. Disc degeneration can lead to acute or chronic low back or neck pain, depending on the location of the affected disc and the amount of pressure it causes. It can cause pain that goes down the leg, called sciatica.
The pain caused by disc degeneration is thought to be derived from inflammation and micromotion instability. Micromotion instability refers to the loss of the ability to resist motion in the spine.
Recent research suggests that type II diabetes (T2D) may be a risk factor for disc degeneration. Diabetes often damages small blood vessels in the body. This damage has been proven to affect intervertebral discs by causing inadequate nutrient supply and accumulation of oxidative toxins in the discs. This can lead to disc degeneration.
Researchers have recently hypothesized that vitamin D may play a role in the treatment and prevention of disc degeneration. This hypothesis was based upon vitamin D’s ability to reduce inflammation and improve markers of insulin resistance (the main characteristic of T2D).
To test this hypothesis, researchers conducted an animal study. A total of 45 rats were divided into three groups:
- Experimental group: Researchers induced T2D. Then, the rats were given calcitriol, active vitamin D.
- Control group: Researchers induced T2D, but no calcitriol was given.
- Normal group: The researchers did not induce T2D, and no calcitriol was given.
The researchers wanted to determine the effects of active vitamin D on the TGF-β and IGF-1 levels, markers used to measure the severity of disc degeneration. Lower TGF-β and IGF-1 levels reflect greater severity of disc degeneration.
Here is what the study found:
- Degenerative changes occurred in the discs of the rats that had T2D but not the group without T2D.
- The growth rate of TGF-β and IGF-1 in the discs of diabetic rats in the experimental group was significantly lower than that of the normal group and higher than that of the control group at three different times (P < 0.05).
- TGF-β and IGF-1 levels were highest in the rats without T2D (P < 0.05).
- TGF-β and IGF-1 levels were significantly higher in the experimental group compared to the control group (P < 0.05).
The researchers stated,
“Vitamin D can protect the degeneration of intervertebral disc and improve the content of TGF-β and IGF-1 in the intervertebral disc, which provides a new idea for the prevention and treatment of degenerative changes of the intervertebral disc in diabetic patients.”
As an animal study, the findings cannot yet be applied to people. However, the findings warrant researchers to conduct clinical trials with humans to determine whether the same effects occur. Furthermore, the study used active vitamin D opposed to the form most commonly used in vitamin D supplements (vitamin D3/D2). The active vitamin D was administered in a very high dose, equivalent to about 40,000 IU of vitamin D3/kg, meaning that a 150 pound person would receive over 2.7 million IU of vitamin D3. Clearly, this dosage would harm humans. Thus, researchers should investigate the benefits of vitamin D3 supplements in safe doses for disc degeneration. Lastly, the experimental group consisted of diabetic rats, which limits the generalizability of the findings to non-diabetic mice.
Overall, the study provided a new and exciting perspective on vitamin D for the treatment and prevention of disc degeneration. Although, the research on this topic remains in its infancy.
Tovey, A. Cannell, J. Vitamin D: a potential treatment for disc degeneration. Vitamin D Council, June 7, 2017.