Diet prescription - IVA

Establishing a prescription is done in a stepwise manner:

Step 1	Fill the leucine requirements through the use of measured quantities of intact protein from breast milk, regular infant formula in infants and by natural food intake beyond infancy
Step 2	Fill the protein requirement by adding the leucine free L-amino acid supplement that provides a leucine free mixture of amino acids, and other nutrients
Step 3	Fill energy requirements by adding non-protein calorie sources as needed. Energy needs should be based on ideal body weight whenever possible and are the same as for non-IVA patients
Step 4	Adjust fluid volume to meet requirements
Step 5	Calculate vitamin, mineral and trace-element content, essential fatty acids (EFA) of the final mixture, adjust or supplement as needed

Dietary recommendations:

Protein recommendations

Standard nutritional management for patients with IVA¹
Age	Protein requirements*(g/kg/day)	Leucine intake** from natural protein (mg/kg/day)	Energy requirements(kcal/kg/day)
Neonates	2.5-3.5	65-150	95-145
Infants	2.0-3.0	50-140	80-135
Young children	1.5-2.0	40-90	60-130
Older children and adults	1.1-1.8	30-60	35-70

* Modified from Acosta and Yanicelli 2001 and Marriage (2010). These recommendations are only a guide and must be individualized for each patient, based on the severity of their disorder. Patients with milder forms of the disorder will tolerate a higher leucine intake and may only require a reduced natural protein diet.

** includes protein intake from leucine free supplements plus natural protein

Fluid requirements, based on requirements of healthy population
Age	Weight (kg)	Recommendation (ml)
0-3 months		150 x weight (kg)
4-6 months		130 x weight (kg)
7-9 months		120 x weight (kg)
10-12 months		110 x weight (kg)
>1 year	1-10	100 x weight (kg)
	11-20	1000 + 50 x (weight in kg – 10)
	> 20	1000 + 20 x (weight in kg – 20)

Human fluid requirements
Report of a Joint FAO/WHO/UNU expert consultation 2001

% of leucine found protein of milk, cereals, vegetables and fruits⁴
Protein source	% Leucine found
Milk, cereals	10-11%
vegetables	3-6 %
fruits	5 %

References:

Knerr I, Vockley J, Gibson KM. Disorders of leucine, isoleucine and valine metabolism. In; Blau N (ed) Physician’s guide to the diagnosis, treatment and follow-up of inherited metabolic diseases, 2^nd Springer Heidelberg, 2014103-142
Acosta PB, Yannicelli S. Maple syrup urine disease. Nutrition support protocols. 2001
Marriage B (2010) Nutritional management of patients with inherited disorders of branched-chain amino acid metabolism. In: Acosta PB (ed) Nutritional management of patients with inherited metabolic disorders, 1st edn. Jones and Bartlett Publishers, Sudbury, pp 175–236
Dixon MD, MacDonald A, White F, Stafford J. In: Clinical Paediatric Dietetics. 4^th ed: West Sussex: John Wiley & Sons Limited, 2014:422.
E-IMD – isovaleric Aciduria: http://www.e-imd.org/en/healthcare-professionals/individual-conditions/organic-acidurias/iva/index.phtml