A new study, published in the journal Nutrients, suggests that more than one in four midlife and older adults (ages 50 and up) living in Northern England are deficient in vitamin D.
Vitamin D plays a significant role in bone health and mood. Low levels of vitamin D have been linked to depressive symptoms, anxiety and seasonal affective disorder (SAD), a form of depression that occurs in the winter months.
Researchers from Trinity College Dublin in Ireland found that more than half (57%) of the 6,004 participants had inadequate serum vitamin D levels, of which 26% were classed as vitamin D deficient.
“The high rates of deficiency are similar to rates seen in other high latitude countries such as Ireland,” said coauthor Dr. Eamon Laird, Trinity Research Fellow.
“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.”
People at greatest risk include females, adults 80 years and older, smokers, people of non-white ethnicity, obese people and those with poor self-reported health.
On the other hand, being of a healthy weight, retired, engaging in regular vigorous physical activity, taking vitamin D supplements, and sun travel in the past 12 months and during the summer season were positive determinants, and therefore potentially protective factors against vitamin D deficiency in older people.
“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,” said first author Dr. Niamh Aspell, who conducted the study as part of her PhD at Trinity.
The researchers also looked at UVB radiation (sunlight), a known determinant of vitamin D status, and found that residents in the South of England had a reduced risk of deficiency, compared with the North, even after adjustment for socioeconomic and other predictors of vitamin D status.
The new findings suggest 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.
“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,” said Maria O’Sullivan, Associate Professor in Nutrition at Trinity College.
“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 ageing. The findings are valuable in developing targeted strategies to eliminate vitamin D deficiency in older populations.”
Source: Trinity College Dublin