Plasma amino acid fractionation

ND-recommended test reviewed: plasma amino acid fractionation.
Indications reviewed: fatigue, general wellness; no features suggestive of an inborn error of metabolism present.
Not ordered. Rationale discussed: amino acid panel is a specialist diagnostic tool for inborn errors of metabolism, not a validated marker of general nutritional or protein status. Ref: Sarker et al 2019, LC-MS/MS diagnosis of inborn errors of metabolism.
Patient informed test available privately via ND. Patient given info page: https://labs.ajaxharwoodclinic.com/amino-acids/patient
Revisit if: features suggestive of an inborn error of metabolism develop or are identified.

Indicated when

• —Suspected inborn error of metabolism (aminoacidopathy) in a patient with compatible clinical features (e.g., unexplained developmental delay, recurrent metabolic decompensation, unusual odour, or a positive/borderline newborn screen), as a specialist metabolic-genetics diagnostic test; plasma amino acid quantitation is used to diagnose more than 30 inborn errors of metabolism [1]

Not indicated when

• —Investigating fatigue, general wellness, athletic performance, or 'protein status' in adults or children without features suggestive of an inborn error of metabolism
• —Routine addition to a wellness or nutrient panel

Why not

Plasma amino acid fractionation is a specialist diagnostic tool for a specific group of rare genetic conditions (aminoacidopathies), not a general marker of nutritional or protein status. Ordered outside that context, an amino acid profile commonly returns borderline or hard-to-interpret variations (amino acid levels are affected by recent meals, fasting state, and overall nutritional status) that do not point to a specific diagnosis or actionable next step, and interpretation of a full amino acid panel outside a suspected inborn error typically requires the same metabolic-genetics expertise the test was designed for.

Better first step

If there is no clinical suspicion of an inborn error of metabolism, address the presenting concern (fatigue, wellness, diet) directly rather than ordering an amino acid panel; if an inborn error is genuinely suspected, refer to or consult metabolic genetics, who can select and interpret the appropriate panel alongside other studies (e.g., acylcarnitines, urine organic acids).

Typical ND rationale

An ND may order a plasma amino acid panel reasoning that it gives a detailed picture of protein and amino acid status, and that identifying individually low or high amino acids can guide targeted supplementation for symptoms like fatigue, mood, or muscle recovery.

Ontario coverage & CONO orderability

OHIP status

insured

Amino acid fractionation and quantitation is listed by name in the 2026 Schedule of Benefits for Laboratory Services (L013 Amino acids, fractionation and quantitation), without a stated clinical-criteria restriction, so it is insured when a physician orders it after clinically assessing the patient [2]. ND-ordered testing is patient-paid regardless of this underlying insured status (Reg. 552 s.22; [5]).

CONO orderable

Yes — CONO list #11

CONO list item 11, blood: 'Amino Acids - Total Fractionation.' Not seen named on any of the 6 Ontario ND clinic pages or 3 lab catalogues fetched for the nd-landscape.md sweep, so it is CONO-listed but not confirmed as commonly marketed in this session's sources.

Linked conditions

• tired ↗

Counselling script

“A full amino acid panel is really a specialist test for diagnosing rare inherited metabolic conditions, and outside that situation the results are hard to interpret because amino acid levels shift with meals and fasting. I don't see features here that suggest one of those conditions, so I wouldn't order this test for fatigue or general wellness. Let's look at more useful things for how you're feeling instead.”

Revisit if

• —Clinical features suggestive of an inborn error of metabolism develop or are identified (e.g., unexplained developmental delay, recurrent metabolic decompensation, unusual odour)

References

1. [1]Sarker et al. (2019). Age-Specific Cut-off Values of Amino Acids and Acylcarnitines for Diagnosis of Inborn Errors of Metabolism Using Liquid Chromatography Tandem Mass Spectrometry. linkQuantitation of amino acids (and acylcarnitines) is used for the diagnosis of more than 30 inborn errors of metabolism
2. [2]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026) - L013 Amino acids. linkAmino acids, fractionation and quantitation is listed by name in the 2026 Schedule of Benefits for Laboratory Services
3. [3]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkCommunity lab tests are insured only when ordered under the Schedule by an authorized prescriber
4. [4]Government of Ontario (e-Laws) (2026). Health Insurance Act, R.R.O. 1990, Reg. 552: General, s. 22 (insured laboratory services). linkA lab test is insured only when ordered by a physician, midwife, or NP who has clinically assessed the patient
5. [5]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkTests ordered by anyone other than an authorized provider, including NDs, are not insured services