Written by Jessica Patella, ND. The study found that participants (23.2%) that had the highest level of vitamin D had the least amount of cognitive impairment.
Research has shown a strong correlation between vitamin D levels and memory decline, although research has been focused on advanced-stage dementia (1,4). Low blood levels of vitamin D are common in both European and US older adults living in community settings (1,4,5). Current research is emerging showing a link between low levels of vitamin D and mild memory loss (1).
Recent research included 95 Caucasian participants without dementia living in a community setting (average age 71.1; 54.7% women) (1). Multiple physicians tested each participant for mild cognitive impairment. Forty-three participants (46.3%) were diagnosed with mild cognitive impairment, indicating mild memory loss (1).
Blood was collected from the participants to determine their vitamin D levels (25OHD). Blood levels of vitamin D were divided into quartiles, as follows:
– First quartile: 10.0-40.0 nM
– Second quartile: 41.0-59.0 nM
– Third quartile: 60.0-79.0 nM
– Fourth quartile: 80.0-189.0 nM
Twenty-two (23.2%) of participants were in the fourth quartile of vitamin D levels, indicating they had the highest levels of vitamin D, within the group 18 were healthy and 4 showed mild cognitive impairment (1). Participants with mild cognitive impairment had lower vitamin D levels (first quartile (25.3%; 10 healthy, 14 mild cognitive impairment), second quartile (27.4%; 13 healthy, 13 mild cognitive impairment) and third quartile (24.2%; 11 healthy, 12 mild cognitive impairment)).
It was also discovered that participants with mild cognitive impairment were less likely to be female (OR -0.11 [95CI: 0.03– 0.40], P = 0.001) and were less likely to be highly educated (implied by completing graduate studies; OR= 0.12 [95CI: 0.03–0.54], P = 0.006) (1).
Researchers suggest that low levels of vitamin D may contribute to changes in blood flow to the brain, resulting in the death of brain neurons and ultimately memory decline (1). It is also hypothesized that vitamin D may reduce the accumulation of Amyloid Beta 42 peptide, which is linked with Alzheimer’s Disease (1).
In conclusion, low blood levels of vitamin D was associated with mild cognitive impairment in older adults (1). Further research with a more diverse population should be conducted.
Source: Annweiler, Cédric, et al. “Vitamin D insufficiency and mild cognitive impairment: cross‐sectional association.” European journal of neurology 19.7 (2012): 1023-1029.
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Posted February 20, 2013.
Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health. She earned her ND from Southwest College of Naturopathic Medicine in Tempe, AZ, and is a member of the North Carolina Association of Naturopathic Physicians. Visit her website at www.awarenesswellness.com.
References:
- Annweiler C, et al. Vitamin D insufficiency and mild cognitive impairment: cross-sectional association. European J Neurology 2012, 19: 1023-29.
- Annweiler C, et al. Vitamin D and aging: neurological issues. Neuropsychobiology 2009; 62: 139–150.
- Grant WB. Does vitamin D reduce the risk of dementia? J Alzheimers Dis 2009; 17: 151–159.
- Annweiler C, et al. Vitamin D and cognitive performance in adults: a systematic review. Eur J Neurol 2009; 16: 1083–1089.
- Llewellyn DJ, et al. Vitamin D and cognitive impairment in the elderly U.S. population. J Gerontol A Biol Sci Med Sci 2011; 66: 59–65.
