Why is Vitamin D important for Brain Health?
Researchers have discovered certain cells in the brain have receptors for vitamin D that keep the brain healthy and functioning.
In animal models of Alzheimer's disease, activated vitamin D helped clear the brain of amyloid, the toxic protein that can boost up and contribute to Alzheimer's pathology.
In a mouse model of Alzheimer's disease, vitamin D was shown to support neurogenesis, of the formation of new health brain cells, which occurs during brain development and may occur in some parts of the brain later in life.
Vitamin D protects against neuro-inflammation and neurodegenerative disorders in animals.
Human studies show that higher vitamin D levels are associated with reduced disability and cognitive impairment following stroke.
Vitamin D and Age-Related Cognitive Decline
The differences in loss of cognitive function in people in the same age group are striking, with some experiencing a rapid decline.
Depending on the severity and quickness of the loss, the decline can be diagnosed as either mild cognitive impairment or dementia.
Mild cognitive impairment appears as a decline in memory function and other mental processing skills. This condition is very common, affecting roughly 15%-20% of all individuals 65 years of age and older. People with mild cognitive impairment are at high risk for dementia.
Dementia is a contributor to death in the elderly, and Alzheimer's disease is the most common cause of dementia.
Approximately 10% of those 65 years and older live with Alzheimer's disease. Over 5 million people in the US suffer from Alzheimer's, and this number is expected to rise in the years to come.
What does this have to do with vitamin D? Low vitamin D levels have been associated with deteriorating brain function, and vitamin D levels have consistently been found tilo be predictive of risk for mild cognitive impairment and dementia. In fact, the risk of developing dementia is greater in those with vitamin D deficiency.
One study found that a person's vitamin D level could protect cognitive problems 13 years later. Those with higher vitamin D levels had less cognitive impairment with better short-term and working memory.
Several other studies found this same link between lower vitamin D levels and the risk for cognitive impairment. In one of those studies, the risk was more than three time greater for those with the lowest levels of vitamin D.
Vitamin D levels also appear to be associated with the structure of the brain. Normal age-related decline in brain function is associated with atrophy, the loss of volume of brain tissue over time.
In one recent study, researchers found that higher vitamin D levels were associated with more beneficial greasy matter in older adults. Gray matter is the brain tissue where nerve cell bodies raise and form functional connections with other cells. This includes the cerebral cortex, which is the major region of the brain that controls cognition, including executive function, new memory formation, and memory recall.
Deficiency of vitamin D is a common problem.
In addition to affecting other systems in the body, receptors for dhr vitamin D are found throughout the brain, tightly linking nervous system function to vitamin D levels.
Vitamin D appears to support brain function and protect against neurodegeneration.
Various cognitive impairments, ranging from mild memory loss to Alzheimer's dementia, have been associated with lower levels of vitamin D.
Scientists recommended those range is 5,000 to 8,000 IU of vitamin D3 salt. Heavier people often need the higher doses and absorption is much better when the vitamin is taken with a meal that contains fat.
Annual blood tests can enable one to know whether they are taking the correct dosage to ensure optimal blood levels of vitamin D.