Vitamin D insufficiency is strongly associated with the development and progression of memory loss, Alzheimer’s Disease and dementia.
Russell Setright, a Short literature review
Alzheimer’s disease is the most common form of dementia, affecting up to 70% of all people with dementia
What is Alzheimer's disease?
Alzheimer’s disease is the most common form of dementia, affecting up to 70% of all people with dementia. It was first recorded in 1907 by Dr Alois Alzheimer. Dr Alzheimer reported the case of Auguste Deter, a middle-aged woman with dementia and specific changes in her brain. For the next 60 years Alzheimer’s disease was considered a rare condition that affected people under the age of 65. It was not until the 1970s that Dr Robert Katzman declared (rather boldly at the time) that "senile dementia" and Alzheimer’s disease were the same condition and that neither were a normal part of aging.
Alzheimer’s disease can be either sporadic or familial.
Sporadic Alzheimer's disease can affect adults at any age, but usually occurs after age 65 and is the most common form of Alzheimer's disease.
Familial Alzheimer’s disease is a very rare genetic condition, caused by a mutation in one of several genes. The presence of mutated genes means that the person will eventually develop Alzheimer's disease, usually in their 40's or 50's. information obtained from Alzheimer’s Australia website.
Vitamin D and Alzheimer’s disease
A review of published studies found that a significant number of Australians and New Zealanders have less than optimal serum vitamin D levels, with mild to moderate deficiency ranging from 33 to 84% depending on age, skin colour and/or those in residential care.
These studies have also reported a significant relationship between low vitamin D status and an increase in the prevalence of diseases including; Alzheimer’s disease, diabetes, CVD, metabolic syndrome, osteoporosis, hypertension, certain cancers, several autoimmune diseases the Flu and all-cause mortality. The data also suggest that normalising blood 25(OH)VitD levels by supplementation with vitamin D3 may have a positive effect in disease prevention.
Low Vitamin D levels is highly prevalent in the elderly and may be involved in the development and progression of Alzheimer's disease. As this remains a public health concern with no current efficient treatment. Vitamin D administration could be a multitarget stabilizing treatment for Alzheimer’s disease since Vitamin D simultaneously targets several factors leading to neurodegeneration through immunoregulatory, antioxidant and anti-ischemic actions, as well as the regulation of, acetylcholine neurotransmitter and clearance of amyloid beta peptide plaques. Littlejohns TJ1, Henley WE1, et al. Vitamin D and the risk of dementia and Alzheimer disease. Neurology. 2014 Sep 2;83(10):920-8.
Studies have found that Vitamin D deficiency is associated with a substantially increased risk of dementia and Alzheimer's disease in older people, according to the most robust study of its kind ever conducted. An international team found that study participants who were severely vitamin D deficient were more than twice as likely to develop dementia and Alzheimer's disease.
One study also found evidence that there is a threshold level of Vitamin D circulating in the bloodstream below which the risk of developing dementia and Alzheimer's disease increases. The team had previously hypothesized that this might lie in the region of 25-50 nmol/L, and their new findings confirm that vitamin D levels above 50 nmol/L are most strongly associated with good brain health. Thomas J. Littlejohns, William E. Henley, et al. Vitamin D and the risk of dementia and Alzheimer disease. Neurology, August 2014
Another study backed these findings. Vitamin D insufficiency among the elderly is highly correlated with accelerated cognitive decline and impaired performance, particularly in domains such as memory loss that are associated with Alzheimer's disease and dementia, researchers with the UC Davis Alzheimer's Disease Center and Rutgers University have found. The effect is "substantial," with individuals with low vitamin D declining at a rate three times faster than those with adequate vitamin D levels. Charles DeCarli, MD et al. Vitamin D Status and Rates of Cognitive Decline in a Multiethnic Cohort of Older Adults. JAMA Neurology, September 2015
Also, regardless of gender and extent of advanced age, individuals with lower Vitamin D levels are approximately twice as likely to exhibit significant cognitive decline over time. In addition, low vitamin D levels at baseline also increases the risk of future cognitive impairment by 2-3 times. Levels and the Risk of Cognitive Decline in Chinese Elderly People: the Chinese Longitudinal Healthy Longevity Survey. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 2016
Although I have only included a few of the many studies that were evaluated, the message is consistent and clear in all of the studies. Vitamin D deficiency is a major health issue and is linked with the development and progression of Alzheimer’s disease.
Although, further studies are urgently needed, in the interim, supplementing with Vitamin D3 to correct these deficiencies mat be an important factor in the reduction of the incidence of Alzheimer’s disease and dementia.