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Vitamin D and Dementia: Does a Deficiency Cause Cognitive Decline?

Written by Miranda Stambler
 about the author
5 minute readLast updated June 1, 2022

A potential connection between vitamin D and dementia may cause concern among seniors. Vitamin D is a fat-soluble vitamin essential to bone health and reducing inflammation, according to the National Institutes of Health (NIH). Many studies show low levels of vitamin D could potentially increase the risk of developing dementia. However, additional research is needed to confirm the connection. Dementia is a generalized medical definition of cognitive decline.

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Can a lack of vitamin D lead to dementia?

Medical research has yet to officially determine whether low vitamin D levels directly lead to dementia. However, a majority of studies have shown an association between the two.
Over 1,500 elderly patients without dementia participated in a cardiovascular health study where serum 25-hydroxyvitamin D (i.e. vitamin D) was tested. Of this group, more than 270 patients had developed Alzheimer’s disease or dementia by a 5-to-6-year follow-up. That is according to the study published in the peer-reviewed journal, Neurology.
When compared to those who had normal levels of the serum, seniors who were vitamin D deficient had a greater risk of developing Alzheimer’s disease or dementia. Seniors who were vitamin D deficient were 51% more likely to develop dementia. The risk increased significantly for those with severe deficiency, with 122% more likely to develop dementia.
BMC Neurology conducted a research analysis of 16 studies in 2014. The results showed an increased risk for Alzheimer’s disease and other types of dementia among those with low vitamin D levels.
Seniors who had moderate vitamin D deficiency were 20% more likely to develop dementia. This increased to 36% more likely to develop Alzheimer’s disease. The study showed those with vitamin D deficiency are of higher risk for Alzheimer’s disease than dementia. Those who were severely deficient had a greater risk of 48% for dementia and 51% of Alzheimer’s disease.
Each study shows a difference in the percentage of increased risk. Both agree that a lack of vitamin D, especially a severe deficiency, has shown a greater risk for some types of dementia. While current research cannot officially determine that low levels of vitamin D are associated with dementia, the vitamin is essential to your loved one’s health beyond memory care.

What are the benefits of vitamin D?

Vitamin D has many medical benefits, especially for bone health. It is essential in helping the body absorb calcium and phosphorus, according to Harvard T.H. Chan School of Public Health.
Seniors with vitamin D deficiency are at a greater risk for falls, according to the Center for Disease Control and Prevention (CDC). This can lead to injuries and fractures, and those with insufficient vitamin D are at greater risk for fractures.

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From the age of 1 to 70, the NIH recommends a daily intake of 15 micrograms (mcg) for vitamin D. This is then increased to 20 mcg daily for seniors 71+.

What causes vitamin D deficiency in seniors?

Seniors are at higher risk of not receiving enough vitamin D. Several factors can cause this, according to the NIH.
  • With age, your loved one’s skin lacks the capability to absorb vitamin D completely.
  • Seniors don’t go outdoors as often.
  • Seniors’ dietary needs aren’t always met.
Lack of vitamin D is connected to bone health and a list of chronic diseases. Below are conditions where low vitamin D could be a contributing factor, according to the NIH:
  • Osteoporosis
  • Cancer
  • Cardiovascular disease
  • Depression
  • Multiple sclerosis
  • Type 2 diabetes
  • Weight loss

How to get more vitamin D

Vitamin D can be consumed through certain foods or absorbed through the skin. Adjusting your loved one’s diet can help ease cognitive decline.
If your loved one needs more vitamin D, there are many ways to incorporate additional sources into their lives.
Below are a few ways to add more vitamin D to your loved one’s life:
  • Eating fatty fish like trout, salmon, and tuna
  • Consuming fish liver oil
  • Adequate exposure to sunshine
  • Using a UV lamp
  • Drinking milk
  • Eating white mushrooms
Supplements are also available to help increase vitamin D intake. Prior to taking any supplements, consult a doctor. Supplements can interact with different medications, and excessive vitamin D can also hinder your loved one’s health.

Talk to a doctor about vitamin D

Vitamin D is essential for your loved one’s well-being. A simple blood test during a routine check-up can determine their current vitamin D levels. Beyond affecting memory, receiving adequate levels of vitamin D is a benefit in many ways. If you are concerned about your loved one’s vitamin D intake, speak with their doctor.
If you are concerned about your loved one’s health or are having trouble taking care of their nutritional and other needs, it may be time to consider memory care options. You can talk with one of OurParents’ Senior Care Advisors to learn more about what services are available to best meet your loved one’s needs.

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  1. American Academy of Orthopaedic Surgeons. (2022, January). Vitamin D for good bone health. OrthoInfo.

  2. Centers for Disease Control and Prevention. (2021, August 6). Facts about falls. Cdc.gov.

  3. Chai, B., Gao, F., Wu, R., Dong, T., Gu, C., Lin, Q., & Zhang, Y. (2019, November 13). Vitamin D deficiency as a risk factor for dementia and Alzheimer’s disease: An updated meta-analysisBMC Neurology.

  4. Chalcraft, J. R., Cardinal, L. M., Wechsler, P. J., Hollis, B. W., Gerow, K. G., Alexander, B. M., Keith, J. F., Larson-Meyer, D. E. (2020, July 27). Vitamin D synthesis following a single bout of sun exposure in older and younger men and womenNutrients.

  5. Harvard T.H. Chan School of Public Health. (2022, January). Vitamin D.

  6. Littlejohns, T. J., Henley, W. E., Lang, I. A., Annweiler, C., Beauchet, O., Chaves, P. H., Fried, L., Kestenbaum, B. R., Kuller, L. H., Langa, K. M., Lopez, O. L., Kos, K., Soni, M., & Llewellyn, D. J. (2014, September 2). Vitamin D and the risk of dementia and Alzheimer diseaseNeurology.

  7. Office of Dietary Supplements. National Institutes of Health. (2022, April 28). Vitamin D.

Meet the Author
Miranda Stambler

Miranda Stambler is a copywriter at OurParents. She is a media industry veteran with news production and print experience. She holds a bachelor’s degree in journalism with minors in English and animal science from North Dakota State University.

Edited byJordan Kimbrell

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