The researchers suspect that anti-migraine medications, as well as diet and behavior changes, may play a role in the apparent protective effect of migraine on cognition.

A large group of women taking part in the Baltimore Epidemiologic Catchment Area Study were examined in an attempt to discover the relationship between migraine headaches and cognitive functioning.

Of the group of 1,448 women, 204 had migraine; all underwent a series of cognitive tests beginning in 1993 and again approximately 12 years later.

The researchers found while the migraine sufferers performed worse on cognitive tests, such as word recall, at the beginning of the study, their performance declined 17 percent less over time than women without migraine.

The women over age 50 with migraine also showed the least amount of cognitive decline on a test used to assess cognitive functioning.

The research team led by Dr. Amanda Kalaydjian of Johns Hopkins Bloomberg School of Public Health, Baltimore say the migraineurs scored lower on tests of immediate and delayed memory at the beginning of the study, but their performance declined significantly less over time compared with that of the nonmigraineurs.

Dr. Kalaydjian says some medications for migraine headaches, such as ibuprofen, may have a protective effect on the memory and may be partially responsible for the findings, but adjustments in diet or behavior might also have had an impact and in some way improve cognition.

Alternative treatments for migraine often includes adequate sleep, along with behavioral and relaxation techniques, and a reduction in caffeine.

The researchers believe it is more likely however that some underlying biological mechanism, such as changes in blood vessels or underlying differences in brain activity, causes the decreased cognitive decline over time and say more research is needed to fully understand how migraine affects cognition.

The study is published in the current edition of Neurology, April 24, 2007.

Older adults are inclined towards lower vitamin D levels because of reduced exposure to the sun and because their skin is less able to produce vitamin D from sun exposure compared with younger adults.

The researchers estimate that 1 in 4 people over age 60 have low vitamin D levels which equates to 12 million people.

Current guidelines recommend that people between the ages of 50 and 69 get 400 international units (IUs) of vitamin D per day and for those over age 70 to get 600 IUs but are based primarily on vitamin D's effects on bone health.

Dr. Houston believes higher amounts of vitamin D may be needed for the preservation of muscle strength and physical function as well as other conditions such as cancer prevention as people become elderly.

Dr. Houston recommends supplements of vitamin D3 because it will convert into an active form that the body can absorb and use.

The study is published in the April issue of the Journal of Gerontology: Medical Sciences.