Low Vitamin D Levels May Increase Risk of Dementia and Stroke

Posted on by Emily Kil

The American Journal of Clinical Nutrition published the results of a research study in 2022 that indicates a vitamin D deficiency may raise the risk for both dementia and stroke. The study analyzed more than 294,000 people in the United Kingdom. Most of the study participants were women over the age of 60.

The technical parameters of the study were described by researchers in this way:

Using blood tests on all participants and neuroimaging tools on about 34,000, researchers looked for associations between vitamin D levels and risks of dementia and stroke. A normal blood vitamin D level was defined as at least 50 nanomoles per liter (nmol/L); a deficiency was defined as less than 25 nmol/L.

Low vitamin D levels were linked with an increased risk of dementia and stroke over the course of 11 years of monitoring study participants. Based on this observational study, people with low vitamin D levels were found to have a 54 percent greater chance of developing dementia compared with people whose vitamin D levels were considered normal. Researchers do make note that these results do not prove that taking extra vitamin D, even if you have a low blood level, can prevent dementia or stroke.

What is Vitamin D?

You undoubtedly have heard of vitamin D. Indeed, if you look even casually at your milk carton, you are apt to see “fortified with vitamin D” on the label. Nonetheless, if you are (understandably) like many, many people, you probably know very little about vitamin D.

Your body requires an appropriate amount of vitamin D. Vitamin D is a nutrient your body needs for building and maintaining healthy bones, according to the Mayo Clinic (and all other reputable medical centers, for that matter). The human body can only absorb calcium, the primary component of bone when vitamin D is present in an appropriate amount in a person’s body.

In addition to bone health, vitamin D also regulates many other cellular functions in your body. Vitamin D has three significant properties that are crucial to overall health and wellness. These properties:

  • Anti-inflammatory
  • Antioxidant
  • Neuroprotective

As a consequence, vitamin D supports:

  • Immune health
  • Muscle function
  • Bone health (as we discussed)
  • Brain cell activity
  • And we now have at least some evidence that proper amounts of vitamin D can be valuable in staving off dementia and preventing strokes

Where Vitamin D Is Not

People generally presume that they can get the necessary nutrients from their diets. The problem is many individuals simply do not adhere to properly balanced diets. Even those women and men who eat fairly healthy diets may not get enough vitamin D from what they eat. The scientific reality is that vitamin D is not naturally found in many foods. With that said, you can get decent amounts of vitamin D from such food items as:

  • Fortified milk
  • Fortified cereal
  • Fatty fish such as:
    • Salmon
    • Mackerel
    • Sardines

Sunshine and Vitamin D

Sunlight is also a source of vitamin D. When you come into contact with the sun, a chemical in your skin is converted into what is known as an active form of vitamin D. This active form of vitamin D is also known as calciferol.

The amount of vitamin D your skin is capable of producing depends on a number of factors:

  • Time of day
  • Season of the year
  • Latitude of where you reside
  • Your skin pigmentation
  • Amount of time you spend out of doors

We are all advised to wear appropriate sunscreen to prevent skin cancer. The proper use of sunscreen decreases vitamin D production. You should not abandon the use of sunscreen in order to up the production of vitamin D from your skin. Rather, you should focus on your diet and consider the possibility you might need to take a vitamin D supplement.

Vitamin D and Older Adults

Many older adults do not have enough regular exposure to the sun for purposes of vitamin D creation. In addition, a good number of seniors do not get enough vitamin D from their diets. This can be because they are not consuming enough food items that contain nutrients. However, some seniors have trouble absorbing vitamin D. Therefore, a vitamin D supplement might be recommended.

If you have questions about vitamin D, consult your doctor. Your doctor can arrange for a simple blood test to ascertain if you have a proper amount of vitamin D in your system. The recommended daily amount of vitamin D is 400 international units for children up to age 12 months. 600 international units are the recommended daily amount of vitamin D for people ages 1 to 70 years. The amount of vitamin D increased to 800 international units for people over 70 years of age.

Other Research on Effects of Vitamin D Supplements on Health and Wellness

Beyond the implications of an appropriate amount of vitamin D in a person’s system, there has been some other research aimed at determining the benefits of vitamin D supplements:

  • Cancer. Findings on the benefits of vitamin D for cancer prevention are mixed as of this time. More research is needed to determine whether vitamin D supplements may reduce the risk of certain types of cancer.
  • Cognitive health. On the other hand, research has established a link between vitamin D and cognition. Research studies demonstrate that low levels of vitamin D in the blood are associated with cognitive decline. With that said, more studies are needed to determine the benefits of taking vitamin D supplements for cognitive health.
  • Inherited bone disorders. Vitamin D supplements can be used to help treat inherited disorders. Particularly, vitamin D supplements can be helpful when a person has an inability to absorb or process vitamin D. This includes inherited bone disorders such as familial hypophosphatemia.
  • Multiple sclerosis. Research suggests that long-term vitamin D supplementation reduces the risk of multiple sclerosis.
  • Osteomalacia. Vitamin D supplements are used to treat adults with severe vitamin D deficiency, resulting in loss of bone mineral content, bone pain, muscle weakness, and soft bones. Medically, this type of condition is known as osteomalacia.
  • Osteoporosis. Studies suggest that people who get enough vitamin D and calcium in their diets can slow bone mineral loss. This helps prevent osteoporosis. It also works to reduce the risk of bone fractures. Your doctor can advise if you need a calcium and vitamin D supplement to prevent or treat osteoporosis.
  • Psoriasis. Applying vitamin D or a topical preparation that contains a vitamin D compound called calcipotriene to the skin can treat plaque-type psoriasis in some people.
  • Rickets. This rare condition develops in children with vitamin D deficiency. Supplementing with vitamin D can prevent and treat the problem.

If you have specific questions about vitamin D and your health, schedule an appointment with your primary care physician to discuss your concerns.