Some signs of the vitamin deficiency include include poor sleep, symptoms of depression, headaches, weak muscles and tiredness.
Vitamin D deficiency increases the risk of dementia, research finds.
Adequate levels of vitamin D could prevent almost one-in-five cases of dementia from occurring, the study estimates.
People with low levels of vitamin D have lower brain volumes and are also at a higher risk of strokes — a condition in which the blood supply is cut off to part of the brain.
Professor Elina Hyppönen, study co-author, said:
“Vitamin D is a hormone precursor that is increasingly recognised for widespread effects, including on brain health, but until now it has been very difficult to examine what would happen if we were able to prevent vitamin D deficiency.”
Researchers examined data from almost 300,000 people in the UK Biobank study.
A genetic analysis of the data suggested that low levels of vitamin D are causing the increase in dementia risk.
Professor Hyppönen said:
“Our study is the first to examine the effect of very low levels of vitamin D on the risks of dementia and stroke, using robust genetic analyses among a large population.
In some contexts, where vitamin D deficiency is relatively common, our findings have important implications for dementia risks.
Indeed, in this UK population we observed that up to 17 per cent of dementia cases might have been avoided by boosting vitamin D levels to be within a normal range.”
Worldwide, vitamin D deficiency is very common.
Changing this could help to reduce the dementia risk for many, explained Professor Hyppönen:
“Dementia is a progressive and debilitating disease that can devastate individuals and families alike.
If we’re able to change this reality through ensuring that none of us is severely vitamin D deficient, it would also have further benefits and we could change the health and wellbeing for thousands.
Most of us are likely to be ok, but for anyone who for whatever reason may not receive enough vitamin D from the sun, modifications to diet may not be enough, and supplementation may well be needed.”
How to correct a vitamin D deficiency
Around one-in-five people are thought to have a vitamin D deficiency.
Some signs of vitamin D deficiency include include poor sleep, symptoms of depression, headaches, weak muscles and tiredness.
A deficiency in this vitamin is particularly prevalent among people with darker skin, who do not leave the house or who are pregnant or have problems with absorption.
Vitamin D supplementation is one option for correcting the problem.
Around 10 mcg per day is the dose often recommended.
A change of diet can also help the problem.
Vitamin D is particularly abundant in foods like milk, liver, fatty fish, and egg yolks.
The study was published in the American Journal of Clinical Nutrition (Navale et al., 2022).
