In March 2018 researchers from Canada published the results of their study to assess whether 4000 IU/day of vitamin D3 supplementation was safe for frail older adults and whether this dose was able to improve their physical performance. A total of 40 older adults with frail or pre-frail characteristics were included in the study and given 4000 IU vitamin D3 and 1200mcg calcium carbonate daily for four months. Physical performance and cognitive health were assessed before and after the study. Results showed that frail individuals had a moderately improved physical performance (improved grip strength in females, and a faster walking speed in both males and females) following the supplementation. Individuals with low vitamin D levels (under 75 nmol/L) showed a greater benefit from the supplementation. Pre-frail individuals and those with sufficient levels of vitamin D (over 75 nmol/L) made no significant improvement in their physical performance.