Abstract We measured the levels of serum folate and vitamin B12 in newly discovered hypothyroid (n = 56) and hyperthyroid (n = 47) patients and in age- and sex-matched control subjects (n = 103). Except for one patient with latent pernicious anemia, serum folate and vitamin B12 levels did not differ greatly in our patients and in our control subjects. Another patient was receiving monthly injections of cyanocobalamin for previously diagnosed pernicious anemia. We conclude that abnormalities of thyroid function per se did not alter serum folate or vitamin B12 levels in our patients. References 1. Lindenbaum J, Klipstein FA: Folic acid clearances and serum folate levels in patients with thyroid disease. J Clin Pathol 17:666-670, 1964.Crossref 2. Hines JD, Halsted CH, Griggs RC, et al: Megaloblastic anemia secondary to folate deficiency associated with hypothyroidism. Ann Intern Med 68:792-805,1968.Crossref 3. Rigas AN, Wilson EA, Montgomery DA: Folic acid metabolism in thyroid disease. Irish J Med Sci 7:255-261, 1968.Crossref 4. Elman A, Einhorn J, Olhagen B, et al: Metabolic studies of folic acid in non-malignant diseases. Acta Med Scand 187:347-352, 1970.Crossref 5. Tudhope GR: The Thyroid and the Blood. Springfield, Ill, Charles C Thomas Publisher, 1971, pp 44-52. 6. Herbert V: Aseptic addition method for Lactobacillus casei assay of folate activity in human serum. J Clin Pathol 19:12-16, 1966.Crossref 7. Spray GH: Improved method for rapid estimation of vitamin B12 in serum. Clin Sci 14:661-667, 1955. 8. Fulthorpe AJ, Roitt IM, Doniach D, et al: A stable sheep cell preparation for detecting thyroglobulin auto-antibodies and its clinical applications. J Clin Pathol 14:654-660, 1961.Crossref 9. Leevy CM, Cardy L, Frank 0, et al: Incidence and significance of hypovitaminenemia in a randomly selected municipal hospital population. Am J Clin Nutr 17:259-271, 1965. 10. Mohamed SD, Roberts M: Abnormal histadine metabolism in thyrotoxicosis in man. Lancet 2:933-935, 1965.Crossref 11. Liethold SL, David D, Best WR: Hypothyroidism with anemia demonstrating abnormal vitamin B12 absorption. Am J Med 24:535-548, 1958.Crossref 12. Tudhope GR, Wilson GM: Deficiency of vitamin B12 in hypothyroidism. Lancet 1:703-706, 1962.Crossref 13. Ziffer H, Gutman A, Pasher I, et al: Vitamin B12 in thyrotoxicosis and myxedema. Proc Soc Exp Biol 96:229-230,1957.Crossref 14. Alperin JB, Haggard ME, Haynie TP: A study of vitamin B12 requirements in a patient with pernicious anemia and thyrotoxicosis: Evidence of an increased need for vitamin B12 in the presence of hyperthyroidism. Blood 36:632-641, 1970.
Archives of Internal Medicine – American Medical Association
Published: May 1, 1975