Spring is usually the season I start spending more time outside. This year, with ongoing pandemic restrictions, our regular exposure outdoors may be reduced; which makes this a good time to talk about our vital sunshine vitamin.
Vitamin D, which is mostly obtained through sunlight, is essential throughout our lives. We often associate it with calcium absorption and bone health, but did you know vitamin D also has anti-inflammatory, antioxidant and neuroprotective properties? Considered a neurosteroid hormone, vitamin D has been of interest in cognitive research for many years due to its role in regulating neurotransmitters (our body’s chemical messengers) and neurotrophins (proteins that regulate nerve cells). Here are some interesting recent findings regarding vitamin D and the brain:
In 2019, a review of 12 high quality studies found a significant positive association between vitamin D deficiency (<20 ng/ml) and the risk of dementia and Alzheimer’s disease (AD).
Studies have consistently found that vitamin D levels are significantly lower in individuals with AD and cognitive impairment compared to healthy adults.
Vitamin D may be helpful in preventing and promoting the clearance of amyloid beta and phosphorylated tau, the hallmarks of AD.
A 2021 study concluded vitamin D supplementation (in association with curcumin) may be especially helpful for individuals with vitamin D deficiency to improve cognitive performance.
Older adults are more vulnerable to deficiency because as we age, our skin’s ability to synthesize vitamin D from the sun is reduced. Other factors that may limit your levels include geographical location and skin colour. There are less UVB rays on the earth’s surface the further you are from the equator and individuals with more melanin have less absorption compared to those with lighter coloured skin. Luckily, researchers have recommended more double blind randomized controlled trials with large sample sizes, standardized doses and comparable cohorts, to strengthen the findings on vitamin D supplementation for the prevention and treatment of dementia.
Surprisingly, 1 billion people worldwide are estimated to be deficient in this fat-soluble vitamin and on average we only obtain 10% of our requirement through food. Supplementing with vitamin D is generally considered safe, but too much can be harmful and it can also interact with certain drugs. A simple blood test can evaluate your levels and your doctor can determine the right dose of vitamin D2 and D3 for you. In the meantime, dietary sources to maximize your intake include:
Oily fish: salmon, mackerel, herring, swordfish or in cod liver oil.
Mushrooms exposed to UV rays/sunlight
Fortified food items: milk, non-dairy beverages, orange juice or various breakfast cereals
How do you plan on getting your vitamin D this year? Tell us in the comments below.
Dr. Romi Fung, ND, M.Sc and Alaina King, M.Sc
Dr. Romi Fung, ND, M.Sc is a Naturopathic Physician practicing in Richmond, BC with clinical interests in working with patients living with dementia. Dr. Romi has completed additional training in the Bredesen Protocol for treating cognitive impairment, as well as graduate studies in Aging and Health. He is currently pursuing a Ph.D in Aging and Health from Queen's University and is an Adjunct Clinic Faculty at the Canadian College of Naturopathic Medicine - Boucher Campus.
Alaina has a MSc in Aging & Health and is the owner of Grey Matters Tx. A registered professional Recreation Therapist and Certified Dementia Practitioner, Alaina has been working with older adults with dementia since 1998. In addition to Recreation Therapy, Alaina has worked in Community Patient Care Coordination and as a Staff Educator and Health & Safety Auditor in Long Term Care.
Medical Disclaimer: This content is not intended to be a substitute for professional medical advice, diagnosis or treatment. Never disregard professional medical advice, or delay in seeking it, because of something you have read on this post.
Chai, B., et al. (2019). Vitamin D deficiency as a risk factor for dementia and Alzheimer’s disease: an updated meta-analysis. BMC Neural (19), 284. DOI: 10.1186/s12883-019-1500-6
Sultan, S., et al. (2020). Low vitamin D and its association with cognitive impairment and dementia. Journal of Aging Research, eCollection 2020. DOI: 10.1155/2020/6097820
Panza, F., et al. (2021). Vitamin D in the development and progression of alzheimer’s disease: implications for clinical management. Expert Review of Neurotherapeutics. DOI: 10.1080/14737175.2021.1873768