Variations in infant and childhood vitamin D supplementation programmes across Europe and factors influencing adherence

Abstract

Background: Nutritional rickets is a growing global public health concern despite existing prevention programmes and health policies. We aimed to compare infant and childhood vitamin D supplementation policies, implementation strategies and practices across Europe and explore factors influencing adherence.

Methods: European Society for Paediatric Endocrinology Bone and Growth Plate Working Group members and other specialists completed a questionnaire on country-specific vitamin D supplementation policy and child health care programmes, socioeconomic factors, policy implementation strategies and adherence. Factors influencing adherence were assessed using Kendall's tau-b correlation coefficient.

Results: Responses were received from 29 of 30 European countries (97%). Ninety-six per cent had national policies for infant vitamin D supplementation. Supplements are commenced on day 1-5 in 48% (14/29) of countries, day 6-21 in 48% (14/29); only the UK (1/29) starts supplements at 6 months. Duration of supplementation varied widely (6 months to lifelong in at-risk populations). Good (≥80% of infants), moderate (50-79%) and low adherence (<50%) to supplements was reported by 59% (17/29), 31% (9/29) and 10% (3/29) of countries, respectively. UK reported lowest adherence (5-20%). Factors significantly associated with good adherence were universal supplementation independent of feeding mode (P = 0.007), providing information at neonatal unit (NNU) discharge (P = 0.02), financial family support (P = 0.005); monitoring adherence at surveillance visits (P = 0.001) and the total number of factors adopted (P < 0.001).

Conclusions: Good adherence to supplementation is a multi-task operation that works best when parents are informed at birth, all babies are supplemented, and adherence monitoring is incorporated into child health surveillance visits. Implementation strategies matter for delivering efficient prevention policies.

Keywords: Europe; fortification; micronutrients; policy implementation; rickets; supplementation.

Figure 1

Professionals responsible for providing child health surveillance (A) and for prescribing vitamin D supplements (B). (A) Child health surveillance is provided by paediatricians in 41% of countries (12/29), followed by a combination of a paediatrician and a general practitioner (GP) in 21% (6/29). In Romania, Ireland, Hungary and Sweden, GPs provide health surveillance (14%, 4/29). Health visitors provide health surveillance in conjunction with: a Youth doctor in Netherlands, Paediatrician in Israel and GP in Denmark, Norway, Estonia and Finland (14%, 4/29). The UK is the only country where health surveillance is provided solely by health visitors. (B) Vitamin D supplements are prescribed by the paediatrician in majority of the countries followed by a combination of paediatrician and general practitioner (GP). In Denmark, vitamin D is prescribed by the health visitor, in Sweden by the ‘well baby clinic’, in Israel by the ‘Mother and Child Health centre’, in Netherlands by the health visitor (HV) or ‘Mother and Child Health centre’. Vitamins are not prescribed but available to buy over the counter in Finland and Ireland. In Estonia and Norway, vitamin D is prescribed by GP or HV, whereas in Lithuania and Romania, it is prescribed by the GP.

Figure 2

Adherence rates for infant vitamin D supplementation in the first year of life in Europe. In the absence of national statistics, the adherence rates given are subjective estimates by experts in the field. Good adherence (≥80% of infants supplemented) is indicated in green, moderate adherence (79–50%) in orange and low adherence (<50%) in red.

Figure 3

Percentage of countries adopting each of the 4 independent significant factors, per adherence groups: good ≥80%, moderate 50–79% and low <50% of infants supplemented during the first year of life.