In order to achieve metabolic stability, dietary treatment of inborn errors of metabolism (IEM) may require restriction of protein (e.g. phenylketonuria, tyrosinaemia, homocystinuria, organic acidaemias, maple syrup urine disease (MSUD), urea cycle disorders), fat (e.g. fatty acid oxidation disorders) or carbohydrate (e.g. glycogen storage disease). Manipulation of dietary intake potentially reduces micronutrient status, and provision of a comprehensive vitamin and mineral supplement may become an essential adjunct to dietary treatment.

Paediatric Seravit and Frutivits are vitamin and mineral supplements that are currently available on prescription. Paediatric Seravit is designed for children between 1-3 years of age but has high amounts of added carbohydrate, restricting its use for patients with IEM with restricted carbohydrate intake. Fruitivits is designed for children over the age of 3 years and is orange flavoured, restricting patient's choice, potentially leading to poor adherence and taste fatigue.

Previous studies show that despite improvements in some nutritional markers using the currently available vitamin and mineral supplements, overall use of the vitamin and mineral supplements was less than prescribed and alternatives are needed to guarantee delivery of micronutrients in children at risk of deficiencies as a result of an essential manipulation of diet in inborn disorders of metabolism. Whilst condition specific formula for IEM often contains added micronutrients, there are global concerns about over- and under-supplementation and the impact on palatability. Consequently, some health professionals advocate the availability of unfortified products to enable individualised tailoring of micronutrient intake using a separate vitamin and mineral supplement. Furthermore, with the advent of pharmacological treatments for some IEM, there is evidence that cessation of specialist formula without significant changes to dietary food intake, commonly leads to deficiencies in several micronutrients.

EasiVits are new vitamin and mineral supplements which contain minimal carbohydrate and are unflavoured. This allows them to be used in carbohydrate restricted IEMs, and patients can also add their preferred flavours via permitted fruit cordials or drinks in order to potentially improve adherence and prevent taste fatigue.

Inclusion Criteria:

• Male and female IEM patients ages 1-16 years.
• Patients diagnosed with an IEM.
• Taking vitamin and mineral supplements for IEM and willing to take the new supplements for 7 days.
• Absence of comorbidities.
• Adherence with dietary management and vitamin and mineral supplements.
• Able to understand and comply with the requirements of the investigation and sign the Informed Consent Form/Assent form.

Exclusion Criteria:

• Age <1 years old.
• Patients with comorbidities.
• Any moderate to severe acute illness which in the opinion of the Investigator would interfere with the study procedures or study outcome.
• History of poor co-operation, non-adherence with dietary management, or poor adherence to investigation procedures.
• Participation in any other studies involving investigational or marketed products concomitantly or within two weeks prior to entry into the study.