Studies have linked low vitamin D with a higher risk of Alzheimer’s disease. However, it’s not clear whether vitamin D supplementation lowers Alzheimer’s risk. You can get vitamin D through sun exposure as well as your diet.

Alzheimer’s disease is the most common form of dementia in older adults. According to the Alzheimer’s Association, 7 million people in the United States are currently living with Alzheimer’s. This number is expected to increase to almost 13 million by 2050.

There’s currently no cure for Alzheimer’s. Additionally, there’s no surefire way to prevent Alzheimer’s from developing, although certain lifestyle choices may help to reduce your risk.

Some research has suggested that vitamin D supplementation may reduce the risk of Alzheimer’s. Continue reading to discover more.

Vitamin D is a crucial nutrient for the brain. Research on animals and cells has shown that the vitamin may help with important brain functions like learning and memory while also fighting against inflammation and protecting neurons.

Some researchTrusted Source has also suggested that it may also help remove harmful amyloid plaques in the brain, which are linked to Alzheimer’s disease.

But while research has indeed linked low vitamin D with a higher risk of Alzheimer’s, it’s not clear whether any aspect of these research results affects humans. More study is necessary to understand the relationship between vitamin D and Alzheimer’s disease.

It’s unclear whether supplementation with vitamin D could reduce the risk of Alzheimer’s. While some studies have found supplementation helpful, other researchTrusted Source did not find enough evidence to support this.

A 2023 studyTrusted Source did find that vitamin D exposure was associated with living longer without dementia and 40% lower dementia incidence in general compared to no vitamin D exposure.

However, a newer studyTrusted Source also found that taking vitamin D3 supplements for over 146 days per year increased the risk of developing dementia and was also correlated with higher mortality rates in people already diagnosed with the disease.

Due to these mixed results, more research is needed to understand whether vitamin D supplements are beneficial for those with Alzheimer’s disease.

Whether vitamin D can help reduce the chance of developing Alzheimer’s disease or not, it’s still a crucial nutrient at any age.

Your body naturally produces vitamin D in response to sunlight. While some research suggests 5 to 30 minutesTrusted Source of sun exposure most days of the week can lead to sufficient vitamin D production, this can vary based on:

  • the season and length of the day
  • whether or not there’s a lot of cloud cover
  • air pollution
  • sunscreen use
  • skin melanin content

Prolonged sun exposure is also linked to the development of skin cancer. As such, it’s also a good idea to enrich your diet with foods that are high in vitamin D.

Some examples of foods that are rich in vitamin D include certain fish, egg yolks, mushrooms, and vitamin D-fortified foods like milk.

The amount of daily vitamin D that’s recommended for you depends on your age. The table below shows daily vitamin D recommendations according to the National Institutes of Health (NIH)Trusted Source.

NIH vitamin D recommendations

AgeRecommended daily vitamin D in micrograms (mcg) and International Units (IU)
Birth to 12 months10 mcg (400 IU)
Ages 1 to 70 years15 mcg (600 IU)
Age 71 and older20 mcg (800 IU)
Pregnant and nursing 15 mcg (600 IU)

What’s the best vitamin to prevent Alzheimer’s?

The National Center for Complementary and Integrative Health (NCCIH)Trusted Source notes that while some studies have shown modest effects for some supplements in preventing cognitive decline and dementia, direct evidence is lacking.

The organization does note that the most consistent positive results have been in studies of omega-3 fatty acid supplements.

How much vitamin D should I take daily to prevent dementia?

A causal link between low vitamin D and dementia has not been proven. However, it’s known that low vitamin D can cause a variety of health problems. As such, it’s always a good general rule to ensure you’re getting sufficient daily vitamin D.

The NIHTrusted Source recommends that most people get 15 mcg (600 IU) of vitamin D each day for general health.

Does vitamin D affect memory loss?

Older researchTrusted Source suggests that there may be an association between severe vitamin D deficiency and memory loss. Animal researchTrusted Source has also found that vitamin D supplements may be able to prevent this, but more study in humans is necessary.

Research has linked low vitamin D with a higher risk of Alzheimer’s. However, the results of studies on whether vitamin D supplementation reduces the risk of Alzheimer’s have been mixed. Overall, more research is needed on this topic.

You can get vitamin D by sun exposure and via your diet. Individuals who cannot get enough vitamin D through these routes may need to take a supplement. Always talk with your doctor before adding any new supplements to your diet.