The human body is meant to be mobile and function without pain, but for people with spinal cord injuries, daily tasks can be much more difficult to carry out than for the average healthy person. Vitamin D has not only been shown to be a predictor of strong and healthy bones, but recent research suggests vitamin D may be involved in skeletal muscle health and function.
People who have chronic SCI (spinal cord injury) are at higher risk of vitamin D deficiency because of factors including increased fat mass, inadequate sunlight exposure, other illnesses and certain medications that decrease nutrient absorption.
Muscle atrophy, a common consequence of SCI, causes a decline in activities of daily living (ADL) and leisure time physical activities (LTPA). This leads to less sunlight exposure and increased fat mass, both of which lead to less vitamin D synthesis.
A recent longitudinal study looked at 67 patients with chronic SCI in a rehabilitation program. Functional independence of activities of daily living (SCIM), LTPA and 25(OH)D levels were measured at admission, and again 1 year later.
Here is what the researchers found:
- A total of 75% of the participants were vitamin D deficient (< 20 ng/ml).
- Baseline vitamin D levels below 18.6 ng/ml was associated with a 2.8 fold increased odds of declining SCIM scores after one year (p = 0.0003).
- Those vitamin D levels below 18.2 ng/ml at baseline had a 2.6 fold increased odds of impaired LTPA scores after one year (p = 0.001).
The researchers concluded,
“In people with chronic SCI, a low 25(OH)D level may represent an independent predictor of worsening in physical function outcomes over time.”
Barbonetti, A. et al. Low vitamin D levels are independent predictors of 1-year worsening in physical function in people with chronic spinal cord injury: a longitudinal study. International Spinal Cord Society, 2018.