Vitamin D, also known as the sunshine vitamin, plays an important role in bone health. However, a new study suggests that people above 50 years are more prone to vitamin D deficiency.
Over a quarter of adults aged 50+ are deficient in vitamin D according to researchers from Trinity College Dublin who announced their findings. Over half (57%) had inadequate serum vitamin D levels, of which 26% were classed as vitamin D deficient. Vitamin D has a known role in bone health, with growing evidence for beneficial effects on muscle strength and other non-skeletal outcomes. The study was recently published in the international, peer-reviewed journal Nutrients.
Better understanding of factors that contribute to vitamin D deficiency is needed to identify people most at-risk. Determinants of deficiency identified in this new study were female gender, advanced age (80+ years), smoking, non-white ethnicity, obesity, and poor self-reported health. Researchers, therefore, identified a profile of older people more likely to be at risk of vitamin D deficiency. Being of a healthy weight, retired, engaging in regular vigorous physical activity, vitamin D supplement use, sun travel in past 12 months and summer season were positive determinants, and therefore potentially protective factors against vitamin D deficiency in older people.
This new research demonstrates that vitamin D deficiency is prevalent in older adult populations living at Northern latitudes and highlights the importance of public health strategies throughout midlife and older age to achieve optimal vitamin D status.
Associate Professor in Nutrition at Trinity College, Maria O'Sullivan commented 'Our study identified factors associated with vitamin D deficiency, including being aged 80+ years, obesity and sedentary lifestyles; all of which are increasing traits in western populations. Furthermore, this is one of the few studies to highlight the importance of non-white ethnicity in vitamin D deficiency in a large study of aging. The findings are valuable in developing targeted strategies to eliminate vitamin D deficiency (at 30nmol/L) in older populations'.
First Author Dr Niamh Aspell, who conducted the study as part of her PhD at Trinity said: 'Those who used a vitamin D supplement, were less likely to be vitamin D deficient as may be expected, but supplement use was low (4.4%) and, therefore, food fortification and other strategies need to be considered at policy level for older populations'.
Co-Author and Trinity Research Fellow Dr. Eamon Laird, said: 'The high rates of deficiency are similar to rates seen in other high latitude countries such as Ireland. However, other more northern countries such as Finland have implemented a successful vitamin D fortification policy which has all but eliminated deficiency in the population. Such a policy could easily be implemented in the UK and Ireland '.