The study, published in Public Health Nutrition, found South Asians did not supplement with vitamin D with intakes from diet alone insufficient to maintain adequate vitamin D status.
“Such low levels of vitamin D intake and vitamin D supplement use in this population group is very concerning,” said lead study author Dr Andrea Darling, from the department of nutritional sciences at the University of Surrey.
“Vitamin D is crucial to ensuring our overall health and a lack of it leads to an increased risk of chronic illnesses putting an additional strain on the NHS.
“Urgent steps are required to remedy this problem and avoid a public health crisis amongst UK South Asians.”
Adding to the challenge is the population group’s traditionally darker skin pigmentation, low sun exposure to the skin due to dress coverage and sun avoidance behaviour.
Vitamin D deficiency worldwide
The research team pointed to recent studies highlighting high rates of vitamin D deficiency (lower than 50 nanomols per litre (nmol/l)) in Western-dwelling South Asians in North America, Europe and Australasia.
Improvement in vitamin D status is likely to help reduce the incidence of a variety of chronic diseases common in Western-dwelling South Asians, such as type 2 diabetes and CVD.
Public health policies devised to deal with this issue could target the foods consumed in this population. For example, the fortification of juice-based drinks may well be viable due to the lactose-avoiding and vegan lifestyle this group follow.
Gram flour could also be fortified with vitamins and minerals, as the food is a common cereal consumed by the population.
However, the UK’s Scientific Advisory Committee on Nutrition (SACN) said there was a considerable lack of evidence regarding vitamin D status in South Asians to justify a separate recommendation for South Asians in the UK.
They also added that it was “certainly plausible that such a recommendation be necessary considering South Asians’ higher vitamin D risk factors than other UK ethnic groups”.
Researchers found that vitamin D intake through diet was low amongst the sample group of 8,024 South Asians (Bangladeshi, Indian, and Pakistani).
With intakes ranging from 1.0-3.0 micrograms (mcg) per day, there was a differentiation in ethnicity, with Bangladeshis having on average higher vitamin D intake (3.0mcg) than Indians (1.0mcg).
However, all of the groups were below both the European Food Safety Authority (EFSA) recommendation (15 micrograms per day) and Public Health England’s recommendation of 10 mcgs per day.
Vitamin D supplementation use was low amongst UK South Asians, with only 22% of Bangladeshis, 32% of Indians and 25% of Pakistanis taking a vitamin D containing supplement.
Within this group, women (39%) were more likely to take supplements than men (23%).
Unexpected results found that South Asians in Greater London had a higher rate of vitamin D intake (35%) than those in other regions in the UK (18-28%).
“The higher vitamin D intake in Bangladeshis is likely due to increased oily fish consumption relative to the other groups,” the researchers suggested.
“Equally, the poor vitamin D intake in Indians is likely due to the high prevalence of vegetarianism in this group. Eggs, cereals and fortified spreads are other sources of vitamin D that may be relevant in this group, but these sources are lower in vitamin D content than oily fish.
“The numbers are generally too small in the Bangladeshi group to make definitive inferences, but it is noteworthy that only 10 % (n 22) of the Bangladeshi group ate oily fish daily.”
Source: Public Health Nutrition
Published online ahead of print: doi.org/10.1017/S1368980018001404
“Vitamin D supplement use and associated demographic, dietary and lifestyle factors in 8024 South Asians aged 40–69 years: analysis of the UK Biobank cohort.”
Authors: Andrea L Darling, David J Blackbourn, Kourosh R Ahmadi, Susan A Lanham-New