Vitamin D is an essential element of the diet and carries several important roles. There are numerous studies that show that vitamin D enhances muscle strength and improve balance in adults. However no evidence is yet found supporting vitamin D improves gait. It is of vital importance to note that the intake of vitamin D has to be at a certain level. Either too much or too little vitamin D can pose a threat on health.
A small 2013 study ( Ceglia et al) was conducted on a group of female involving the consumption of a capsule containing 4000Iu of vitamin D3 post-breakfast, daily for a period of four months. The participants selected for this study were 65 years of age or older with limited mobility and a moderately low level of vitamin D3.
Results showed a 10% increase in muscle fibre size in the supplemented group when compared to the placebo group. In addition there was a 30% increase in vitamin D3 receptors on muscles cells and a rise in vitamin D levels were found in the supplemented group. The rise in the number of receptors suggested an alteration in muscle metabolism and function. Other findings found indicated no effect on knee extension power or physical functioning.
Another study (Cangussu et al 2015) conducted on postmenopausal Brazilian women involved the intake of 1000IU vitamin D3 as a liquid form over a period of 9 months. The women had a history of falls and were deficient in vitamin D. Results showed vitamin D levels has increased to the average level of 27.5ng/ml. Moreover, a chair rising test revealed a 25.3% increase in muscle strength. A handgrip test was also administrated, however no significant increase in handgrip strength was found. Lastly, results showed women receiving a regular intake of vitamin D maintained lean mass, whereas women in the placebo group lost lean mass.
A 2-year study (Uusi-Rassi et al 2015) involving women from Finland aged 70 to 80 years of age with average levels of vitamin D3. The study concluded that receiving a further supplementation of vitamin D3 did not cause a decline in the number of falls experienced. Furthermore, women who received vitamin D3 tended to fail more in a ‘get up and go’ test, despite an increase in average levels of vitamin D in blood, when compared to the women in the placebo group.
A handful of women in this trial were also enrolled into routine exercises and training classes. These women experienced less injurious falls than those who did not exercise, but without a reduction in the overall number of falls. However, these women who exercised displayed improved mobility, balance and muscle strength when compared to women who did not train. Although trainers receiving vitamin D showed less benefits that those that were on a placebo, other findings suggested the women receiving vitamin D had increased bone density and a small effect on bone loss in the hips.
In conclusion, the studies mentioned above suggest receiving vitamin D is only beneficial for women with low levels of vitamin D.