Vitamin D is a unique vitamin which can be ingested as well as synthesized by human body. Vitamin D is available in diets and can also be produced by human skin in presence of sun light. People exposed to sunlight regularly do not need any supplement. In places where people do not get enough sunlight in certain periods of the year such as in winter, they have to depend on vitamin D rich food and vitamin D supplements.
There are five forms of vitamin D out of which two forms D2 (ergocalciferol) and D3 (cholecalciferol) are important for humans and are biologically inactive precursors which are transformed in the livers and kidneys into 25- hydroxyvitamin D (25(OH)D), the non-active ‘storage’ form, and 1,25-dihydroxyvitamin D (1,25(OH)2D).
A new study in France indicates that higher intake of vitamin D by people may put them at a lower risk against developing Alzheimer’s disease. As reported by the researchers in the Journal of Gerontology: Medical Science, the highest average intakes of vitamin D were associated with a 77% decrease in the Alzheimer’s.
The researchers led by Cedric Antweiler from Angers University Hospital stated “To the best of our knowledge, the present study is the first one to use a prospective design, allowing us to conclude that the low consumption of vitamin D precedes the onset of Alzheimer’s disease, although eating lots of vitamin D rich foods is associated with a lower risk of developing Alzheimer’s disease,”
It has been known that amyloid beta protein is the core component of the destructive plaques in the brain leading to loss of cognitive function and increased risk of Alzheimer’s , a common form of dementia affecting 13 million people in the world. Vitamin D3 may activate key genes and networks to help trigger the immune system to get rid of the amyloid beta protein.
Alzheimer’s is a non-curable disease taking away thought processes and daily functions from the patients and putting a big burden on the caregivers and the family members. The direct and indirect cost of Alzheimer care is over $ 100 billion in the US.
In the French study, 498 women with an average age of 79.8 years who did not take any vitamin D supplement were studied and followed up for seven years. The dietary intakes of the Vitamin D by the participants were assessed using Food Frequency Questionnaire (FFQ).
It was found that ” women with lower Vitamin D intakes (50 micrograms per week) at the start of the study had a greater risk of developing Alzheimer’s compared with women with higher intakes (59 micrograms per week)”.
“In addition, the highest average intakes of vitamin D were associated with a lower risk of Alzheimer’s, compared with lower intakes.”
Annweiler and co-workers of the study group commented that the potential mechanism of protection of Vitamin D works by influencing the reduction and clearance of beta-amyloid proteins and is linked to protection of hippocampus in rodents.
“The potential brain benefits of the vitamin may also be linked to the nutrient content of vitamin D-rich foods, such as fish. “In particular, there is reasonably good evidence that eating fish reduces the risk of dementia including Alzheimer’s.”
“This effect is generally attributed to the omega-3 polyunsaturated fatty acids even if data are conflicting.” “
There are also other consequences of low intake of vitamin D apart from Alzheimer’s disease. Low intake of vitamin D in adults may cause or aggravate “osteopenia, osteoporosis, muscle weakness, fractures, common cancers, autoimmune disease, infectious diseases and cardiovascular diseases.” There is also evidence that vitamin D may reduce “incidence of type-1 and 2 diabetes.”
Many people just don’t get enough sunshine for their bodies to make enough vitamin D to reduce their risks of these medical conditions. It is recommended that everyone take 2,000 to 5,000 units of vitamin D daily to help them sustain adequate levels.
[Source: This write up is sourced from the article “Increased vitamin D intakes may reduce Alzheimer’s risk” By Stephen Daniells, 23-Apr-2012 in nutraingredients-usa.com]