. 2021 May 25;28:100771. doi: 10.1016/j.ymgmr.2021.100771

Table 2.

Proposed assessments for nutritional status. Frequency of all assessments may be increased if there is a clinical reason for concern or according to the centre's current follow-up protocol.

Assessment	Details	Frequency during titration and dosing optimisation	Frequency during maintenance and diet normalisation
Consensus group recommendations forminimalnutritional status assessments


Blood Phe concentrations	- Primary biomarker of blood Phe control	- Monthly regular follow-up	- Monthly regular follow-up
		- Every 2 weeks in case of LBP (blood Phe <30 μmol/L)	- Every 2 weeks in case of LBP (blood Phe <30 μmol/L)
		- More frequently upon the metabolic team's discretion	- More frequently upon the metabolic team's discretion
Anthropometric evaluation	- Weight, height and BMI	- Up to once per month	- Every 6 months
Anthropometric evaluation	- Waist circumference	- Up to once per month	- Every 6 months
Nutritional intake assessment	- Food frequency questionnaire (preferred)	- Once per month	- Every 6 months
	- 24-h recall records or 3-day food records
	- Food neophobia questionnaire (optional)

Assessments for nutritional status evaluationstrongly recommendedby the consensus group


Blood analysis (in addition to Phe)	- Full amino acid profile, including tyrosine	- Every 6 months	- Annually
	- Full amino acid profile, including tyrosine	- Tyrosine concentrations assessed with blood Phe	- Tyrosine concentrations assessed with blood Phe
	- Prealbumin
	- Full blood cell count
	- Functional markers of micronutrients
	• Ferritin
	• Total homocysteine or methylmalonic acid
	- Micronutrients
	• Folic acid
	• Vitamin B12
	• Vitamin D
	• Iron
	• Calcium
	• Zinc
	• Selenium


Assessments for nutritional status evaluationrecommendedby the consensus group


Body composition analysis	- Fat-free mass and body fat	- Every 6 months or once yearly	- Once yearly
Body composition analysis	- Phase angle obtained from bioelectrical impedance analysis (optional)	- Every 6 months or once yearly	- Once yearly

Bone mineral density	- DXA scan to exclude osteopenia and osteoporosis	- Every 3–5 years	- Every 3–5 years
Bone mineral density	- Per EU PKU guidelines, this should be done based on identified risk, but not essential in routine follow-up [2]	- Every 3–5 years	- Every 3–5 years

BMI: body mass index; DXA: dual-energy x-ray absorptiometry; LBP: low blood Phe, Phe: phenylalanine, PKU: phenylketonuria.