Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2000 Apr;136(4):545-7.
doi: 10.1016/s0022-3476(00)90022-2.

Increased risk of vitamin B12 deficiency in patients with phenylketonuria on an unrestricted or relaxed diet

M Robinson  1 , F J White, M A Cleary, E Wraith, W K Lam, J H Walter
Affiliations
Comparative Study

Increased risk of vitamin B12 deficiency in patients with phenylketonuria on an unrestricted or relaxed diet

M Robinson et al. J Pediatr. 2000 Apr.

Abstract

Objective: To investigate whether dietary relaxation or cessation in patients with phenylketonuria (PKU) predisposes to vitamin B12 deficiency.

Study design: Patients with PKU aged 11 to 38 years underwent a neurologic examination and dietetic assessment and were divided according to their diet into 1 of 3 groups: Strict - those on a strict low phenylalanine (phe) diet with amino acid, mineral, and vitamin supplements; Relaxed - those on a total protein intake of approximately 1 g/kg/d with 50% of this from natural protein and 50% from amino acid, mineral, and vitamin supplements; Unrestricted - those on no formal protein restriction and not taking amino acid supplements. Assays of blood samples were taken for vitamin B12 and folate levels by standard assays. Results were analyzed with Student t test.

Results: Vitamin B12 levels were significantly lower in the PKU groups on relaxed or unrestricted diets compared with the normal population (P <.0001 [unrestricted] and.0034 [relaxed]). Folate levels were significantly elevated in all PKU groups (<.0001).

Conclusion: Patients with PKU who are no longer under strict dietary control may be at risk from vitamin B12 deficiency. We recommend that all patients should remain under medical and dietetic supervision and in particular have their vitamin B12 status monitored.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types