Vitamin D intake has long been associated with the maintenance of bone health in older adults, but also in the management of Dementia.
Many studies have established the importance of adequate Vitamin D levels in the management of various conditions including cognitive decline, dementia, depression, cardiovascular disease, hypertension, type 2 diabetes, and cancer (Meehan & Penckofer, 2014; Giustina, Bouillon, Dawson-Hughes, & Ebeling, 2023).
Cognitive decline is a devastating condition that includes a spectrum of illnesses, ranging from mild cognitive impairment to the advanced stages of dementia (Meehan & Penckofer, 2014).
According to recent statistics published by Dementia Australia, there are 487,500 Australians living with dementia and without a medical breakthrough, this number is expected to increase to over 800,000 by 2058 (Dementia Australia, 2023).
Hence, alternative strategies, including the role of Vitamin D, are being explored in the management of dementia progression.
Studies show low vitamin D levels in older adults are associated with an increased risk of cognitive decline (Chan & Woo, 2011; Annweiler, Montero-Odasso, & Llewellyn, 2013; Llewellyn, Langa, & Lang, 2010).
One study found the risk of developing all-cause dementia increased by 51% in participants with Vit D deficiency compared to participants with normal serum Vitamin D levels (Littlejohns & Henley, 2014).
The Australian Guidelines recommend 15.0 µg /day of Vitamin D for adults aged >70 years. Higher levels are recommended for older adults because of the reduced capacity of the skin to produce vitamin D and reduced exposure to sunlight in older adults. (Nutrient Reference Value for ANZ, 2023).
Vitamin D can be obtained through the following sources (Meehan & Penckofer, 2014).
It is difficult to obtain adequate Vit D from food alone. Food source of Vit D include:
The best source of Vit D is sunlight. UV radiation from the sun causes a chemical reaction which converts 7-dehydrocholesterol in the skin to active Vit D.
Seasonal changes have a significant effect on the production of Vitamin D. Vitamin D deficiency is more common in the winter months due to decreased sunlight and also people covering up more.
Summer: A few minutes of direct sunlight mid-morning/afternoon daily to arms and hands (or equivalent area of skin)
Winter: 2-3 hours over a week
Older adults with darker skin may need longer exposure to the sun to obtain adequate Vit D levels. (Cancer Council)
Sun exposure in older adults may be difficult, especially for those who are bed bound.
Therefore, supplementation has been considered a safe and cost-effective method of managing Vitamin D deficiency. (Holick, 2011).
The Institute of Medicine’s supplementation guidelines recommend consumption of 800IU (20 µg) of Vitamin daily for adults >70 years old (Institute of Medicine, 2010), slightly higher than for the general population.
Cognitive decline and dementia are complex conditions which can leave sufferers and their carers desperate for answers.
It is important to acknowledge that while there is currently no cure for these conditions, symptoms and progression can be managed through various medical, nutritional and lifestyle strategies, with adequate Vitamin D intake being an avenue to explore.
Always consult your dietitian and medical team when deciding which option is most suitable for you or the older adults in your care. Contact your Food Solutions Dietitian for support.
