Few multivitamin products for children supply the recommended dose of 400 IU a day of vitamin D, suggest the results* of a survey of 91 different products, published online in the Archives of Disease in Childhood.
Supplements containing only vitamin D or labelled specifically ‘for healthy bones’ typically had a higher vitamin D content, although some products contained very low levels of the vitamin.
Low levels of vitamin D are common in children in the UK, particularly during the winter and in 2016, Public Health England recommended a daily dose of 400 IU (10 ug) all year round for all 1-4 year olds, and during the autumn and winter months for adults and children over the age of four.
The Healthy Start scheme, a public health initiative for low income families in England, provides free multivitamins but these products contain only 300 IU per day of vitamin D, prompting the researchers to see if other children’s multivitamins might contain less than the recommended amount.
In September 2018, they searched the websites of nine UK supermarkets and high street health product retailers, looking for multivitamins aimed at children under the age of 12, and found 67 made by 24 different manufacturers. They also looked at products labelled as a vitamin D supplement, or which suggested they could help with ‘healthy bones’, and found 24 products aimed at children under the age of 12.
The daily vitamin D dose in the multivitamins surveyed ranged from 0 to 800 IU. Only one multivitamin was suitable for use from birth, supplying 200 IU/day of vitamin D, while for children over six months, only between a quarter and a third (25-36%) of the available products supplied at least 400 IU/day.
The vitamin D/healthy bones typically had a higher vitamin D content than multivitamins: nearly two thirds (57-67%) contained at least 400 IU/day. However, one product labelled as ‘for bones and relaxation’ contained only 50 IU/day of vitamin D and only six were suitable for use from birth, five of which contained 340-400 IU of vitamin D.
The researchers point out that their survey was limited to supplements sold by UK retailers, and many other supplements are available from online retailers, including imported products and fortified food products.
“There is a wide range of both multivitamins and vitamin D supplements available for children in the UK, yet most of these do not provide the recommended 400 IU/day,” they write. To obtain this, children would either have to take over the recommended dose, which may increase the risk of toxicity from the other components, or they would have to take a combination of vitamin D and multivitamins, which is more expensive, the authors warn.
Parents and caregivers need to check that the multivitamins they buy for children contain at least 400 IU/day, they advise, and should be aware that as multivitamins are classed as food products, under European Union regulations, the permissible vitamin D content can range from 20% below, to 50% above, the amount stated on the label.
Dr Carrie Ruxton from the Health & Food Supplements Information Service (HSIS) said: “Food supplements are meant to supplement the diet, not replace the nutrients obtained from foods. In that respect, and since there are varying recommendations across different age groups of children, it is right that different supplements offer different doses. Smaller doses allow parents to use the same product for younger and older children by varying the amount given.”
She added: “According to the most recent National Diet and Nutrition Survey (NDNS) data**, children and adolescents are only getting a fifth of the recommended vitamin D intake of 10mcg from food alone. Many of the supplements in this survey would actually bridge the dietary gap topping up intake towards the recommended 10mcg daily.”
*Moon RJ, Curtis EM, Cooper C, et al. Vitamin D supplementation: are multivitamins sufficient? Archives of Disease in Childhood Published Online First: 25 February 2019. doi: 10.1136/archdischild-2018-316339
**List of tables for Years 7-8 of the UK NDNS Rolling Programme (2014/15-2015/16). National Diet and Nutrition Survey data,