Parents and caregivers have been advised to check the amount of vitamin D in multivitamin supplements for children after a study found many such products do not contain the UK’s recommended daily vitamin D dose for children under four.
Published in the Archives of Disease in Childhood, the UK observational study on supplements containing vitamin D for children under 12 years of age found only one-quarter to one-third of multivitamins marketed for children provided the recommended daily dose of 400 international units (IU) of vitamin D for children under four.
Between October and March it is not possible to get enough vitamin D from sunlight in Ireland. This is why intake of foods rich in vitamin D or vitamin D supplements is recommended.
The survey of 91 different products from nine UK supermarkets and high-street health products retailers found the daily vitamin D dose in the products ranged from 0 to 800IU.
“Multivitamins typically had lower vitamin D content than pure vitamin D supplements or ‘healthy bones’ products, although some products labelled as ‘for bones’ contained very low levels of vitamin D,” the study found.
Because multivitamins are classed as food products under EU regulations, the permissible vitamin D content can range from 20 per cent below to 50 per cent above the amount stated on the label, the researchers noted.
It is estimated that up to one in five adults and between eight and 24 per cent of children in the UK are at risk of vitamin D deficiency, which can cause rickets, brittle bones and hypocalcaemia (low levels of calcium in the blood).
A spokesman for the Irish Health Trade Association (IHTA) said no data exists on the sale of vitamin D supplements and multivitamins in Ireland.
It is estimated, however, that annual food supplement sales here amount to €50 million.
‘Maintain health’
A study of vitamin and mineral consumption conducted by the IHTA last year found that more than 71 per cent of respondents purchased health vitamins and minerals.
The majority of buyers did so all year round to “maintain and improve ongoing adult health”.
Almost one-quarter of those purchasing vitamins and minerals did so to “support children’s normal development”, the study revealed.
Dr Eleanor Higgins, consultant dermatologist at the St John's Institute of Dermatology, London, said patients regularly ask GPs about their vitamin D levels and request testing.
Speaking at the Primary Care Dermatology Society of Ireland conference in Galway recently, Dr Higgins said sunlight and diet were the two main sources of vitamin D.
Vitamin D toxicity is rare and only occurs if individuals take high doses of vitamin D for long periods of time, she added.
Those most at risk of vitamin D deficiency include frail, older, institutionalised individuals and obese men and women, among others.
Dr Mary Rose Sweeney, associate professor of health systems research at DCU, said research has found vitamin D is added to a wide range of food products in Ireland.
“We have recently completed a very comprehensive audit of all food staples typically fortified with micronutrients for sales in the supermarkets (at two timepoints 2014 and 2017) with the leading market share in Ireland. Vitamin D appears to be added to a fairly wide range of products.”
The data is currently being analysed and will be available in the coming months.
Authority’s advice
Individuals should eat foods rich in vitamin D or take a supplement that contains vitamin D, especially during autumn and winter, the Food Safety Authority of Ireland (FSAI) advises.
A supplement which provides a maximum of 200-400IU of vitamin D per day is recommended.
An FSAI spokeswoman said food (including supplements) needs to provide 200IU of vitamin D daily for everyone aged five and over.
“In line with national health policy in Ireland, the advice for infants (0-12 months) is a 5µg [200 IU]vitamin D-only supplement daily, regardless of whether the infant is being breastfed or formula fed,” the spokeswoman said.
Guidelines from the UK National Institute for Health and Care Excellence (NICE) recommend that everyone takes 400IU of vitamin D daily during winter months, except for bottle-fed babies under the age of one year, as infant formula is fortified with vitamin D.
Public Health England recommends vitamin D supplementation with 400IU daily year round for children aged one to four, and during autumn and winter for individuals over four years of age.