Vitamin D (actually, a hormone) appears to play a wide variety of roles in health and disease. Back in 2007 I reported on a study which found that higher levels of vitamin D were associated with better physical functioning in the elderly over time. This may not come as too much of a surprise when we consider the evidence that vitamin D has the ability to preserve muscle, and enhance balance and reaction times.
The role vitamin D has here may have particular relevance to the elderly. As we age, we can be at increased risk of frailty and falls. It is possible, therefore, that maintaining higher levels of vitamin D might help preserve functioning and prevent falls in later life.
The study I reported on back in 2007 has validity, I think, but we’re limited in what we can learn from it due to it being ‘epidemiological’ in nature. Because of this, all it can tell us is that vitamin D is associated with improved function. We can’t tell if there’s a causal relationship here from this study. Even if there is, perhaps vitamin D does not cause improved function, but the other way round (improved function might lead to enhanced sunlight exposure and higher vitamin D levels).
I was therefore interested to read a recent study in which vitamin D therapy was tested in group of elderly individuals (average age 70). The study participants were divided into four groups:
Group 1 received 300,000 IU of vitamin D into the muscle
Group 2 received a placebo injection into the muscle
Group 3 received 300,000 IU of vitamin D as an oral supplement
Group 4 received an oral placebo
The group underwent a range of assessments at the start of the study and one month later.
Here are the changes seen after a month in each of the four groups:
Group 1. Reduced pain, improved functional mobility, improved quality of life, improved general health, improved mental health, improved social functioning.
Group 2. Reduced pain, improved physical functioning.
Group 3. Reduced pain, improved physical functioning.
Group 4. Reduced pain.
Overall, compared to placebo, just one big dose of vitamin D had significant benefits for this population, particularly when given directly into the muscle.
We have some evidence here, that vitamin D can directly enhance functioning in the elderly. It makes me think that many elderly individuals can get quite easily get caught in a cycle of impaired functioning, restricted movement, reduced sunlight exposure and then suboptimal vitamin D leading to impaired functioning and so on and so forth. ‘Institutionalised’ individuals in nursing and care homes may be at particular risk, as may any individuals who are long-stay patients in hospital.
It’s impossible to know what sort of disease and disability burden is caused by suboptimal levels of vitamin D, though my suspicion is that it’s sizeable. On the plus side, it’s a problem that is easily tested for and treatable. Growing awareness of this issue may see many more individuals getting the management they require in later life to keep them alive and well.
References:
1. Sakall H, et al. The effect of oral and parenteral vitamin D supplementation in the elderly: a prospective, double-blinded, randomized, placebo-controlled study. Rheumatol Int. 2011 May 10. [Epub ahead of print]
