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Vitamin D Delivers for Cognitive Health

It has been estimated that at least half of the world’s population is deficient in vitamin D. The result can be lowered immune resistance, increased risk of bone fracture, and cognitive decline.

This clinical study found that individuals 65 and older supplementing with vitamin D for 12 months significantly improved scores in a variety of tests, including full-scale intelligence quotient (a test of complete intelligence), verbal short-term memory, vocabulary, block design (matching color patterns printed on blocks), and picture arrangement scores (creating a rational narrative by rearranging random comic-like panels so they present a proper story).

One of the reasons that vitamin D was so effective is that it reduced the damage to telomeres, the protective caps on the ends of chromosomes. Think of telomeres as being similar to the caps on the ends of shoelaces, which prevents them from unraveling. In a similar way, telomeres prevent damage to the DNA, and stop that strand of critical cellular information from unraveling, too.

Telomere damage has been linked to many conditions we associate with aging, including heart disease, type 2 diabetes, cancer, chronic pain, and memory and cognitive issues. This study shows that vitamin D supplementation, a simple addition to anyone’s daily regimen, can dramatically improve the health and abilities of the mind as we get older.


Yang T, Wang H, Xiong Y, Chen C, Duan K, Jia J, Ma F. Vitamin D Supplementation Improves Cognitive Function Through Reducing Oxidative Stress Regulated by Telomere Length in Older Adults with Mild Cognitive Impairment: A 12-Month Randomized Controlled Trial. J Alzheimers Dis. 2020;78(4):1509-1518.

Background: Cognitive decline in older adults is a serious public health problem today. Association between vitamin D supplementation and cognition remains controversial.

Objective: To determine whether a 12-month vitamin D supplementation improves cognitive function in elderly subjects with mild cognitive impairment (MCI), and whether it is mediated through the mechanism in which telomere length (TL) regulate oxidative stress.

Methods: This was a double-blind, randomized, placebo-controlled trial in Tianjin, China. Participants were all native Chinese speakers aged 65 years and older with MCI. 183 subjects were randomized to an intervention group (vitamin D 800 IU/day, n = 93) or a placebo group (the matching starch granules, n = 90), and followed up for 12 months. Tests of cognitive function and mechanism-related biomarkers were evaluated at baseline, 6 months, and 12 months.

Results: Repeated-measures ANOVA showed substantial improvements in the full-scale intelligence quotient (FSIQ), information, digit span, vocabulary, block design, and picture arrangement scores in the vitamin D group over the placebo group (p < 0.001). Leukocyte TL was significantly higher, while serum 8-OXO-dG, OGG1mRNA, and P16INK4amRNA revealed greater decreases in the vitamin D group over the placebo group (p < 0.001). According to mixed-model repeated-measures ANOVA analysis, vitamin D group showed a significant enhancement in the FSIQ score for 12 months compared with the control (estimate value = 5.132, p < 0.001).

Conclusion: Vitamin D supplementation for 12 months appears to improve cognitive function through reducing oxidative stress regulated by increased TL in order adults with MCI. Vitamin D may be a promising public health strategy to prevent cognitive decline.

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Terry is happy to provide his opinion on diet and nutrition, supplements and lifestyle choices. This information is for educational purposes only. It is not meant to replace the advice of your physician and is not to be considered medical advice, diagnosis or treatment. Should you have any concerns please contact your physician directly.
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