Researchers from Wake Forest University School of Medicine in
Winston-Salem, North Carolina, recruited 976 people aged 65 or
older from two towns in the Chianti area of Italy. Scientists
measured physical performance including walking speed, ability
to stand up from a seated position, ability to maintain balance
in several increasingly difficult postures and hand grip
strength. Those who had low levels of vitamin D scored 5% to 10%
lower in physical performance tests and hand grip strength than
those with higher levels. Research does not show that low
vitamin D levels cause poor physical performance, but doctors
noted that muscles need vitamin D to function properly.
Separately, medical experts from Harvard Medical School have
recently concluded that the optimal level for vitamin D begins
at 75 nanomoles per liter of blood (nmol/L). In the Chianti
study, nearly 75% of women and 51% of men had insufficient
levels of vitamin D, meaning 50 nmol/L or less. Approximately
29% of women and 14% of men were deficient