Dublin, Ireland: Vitamin D deficiency may lead to depression in later life, finds a new study. The study by researchers from The Irish Longitudinal Study on Ageing (TILDA) has shown for the first time that vitamin D deficiency is associated with a substantial increased risk of depression (+75%), over a follow-up period of over four years.
Findings of the study, published in the Journal of Post-Acute and Long-Term Care Medicine (JAMDA), are important, given the high prevalence of vitamin D deficiency among older people. Also, the supplementation has a low toxicity risk or side effects. And, depression can have a significant adverse effect on functional status and longevity in later life.
Vitamin D, also called the ‘sunshine vitamin’ is essential for bone health. Its deficiency has been linked with other non-bone health outcomes such as diabetes and inflammation in recent studies. Small studies have linked vitamin D and depression but few have followed up with the same affected people over time, while others have not taken into account other factors that can also affect depression.
Robert Briggs, Specialist Registrar in Geriatric Medicine, St James’ Hospital Dublin, and colleagues investigated the links between depression and vitamin D in older Irish adults an then re-examined the participants four years later to see if vitamin D status affected the risk of developing depression.
- The incident depression group (400/3965) had a higher likelihood of baseline vitamin D deficiency.
- Vitamin D deficiency was associated with a 75% increase in the risk of developing depression by 4 years
- This finding remained robust after controlling for relevant covariates including physical activity, chronic disease burden, cardiovascular disease, and antidepressant use.
The authors suggest that the findings could be due to the potential direct effect of vitamin D on the brain. Given the structural and functional brain changes seen in late-life depression, vitamin D may have a protective effect in attenuating these changes. Similarly, other studies have shown that vitamin D status has also been linked with neurodegenerative conditions such as dementia, Parkinson’s disease, and Multiple Sclerosis.
The findings are significant as status of vitamin D is relatively easy and can be modified in a cost-effective manner through fortification or supplementation.
“This is the largest representative and most comprehensive study of depression risk and vitamin D status in older adults ever conducted in Ireland. Our findings will provide useful information to help inform public health policy – particularly regarding the proposition of the usefulness of vitamin D treatment/supplementation for depression,” said Briggs.
“Given that vitamin D is safe in the recommended intakes and is relatively cheap, this study adds to the growing evidence on the benefits of vitamin D for health. It also helps to continue to impress the need on our public health bodies to develop Irish vitamin D recommendations for the general public. Up to this point, these are severely lacking,” says Dr. Eamon Laird, Research Fellow with TILDA.
“Our findings demonstrate that vitamin D deficiency is associated with a significant increase in the likelihood of developing depression in later life,” concluded the authors.
For further reference log on to https://doi.org/10.1016/j.jamda.2018.10.006