Blood glucose rise following prenatal vitamins in gestational diabetes

J Am Coll Nutr. 1993 Oct;12(5):543-6. doi: 10.1080/07315724.1993.10718350.


Optimal outcome of gestational diabetes mellitus (GDM) is directly related to glucose control of the mother. If prenatal vitamins cause a large glycemic excursion, then the best prenatal vitamin would be one that produces the lowest blood glucose. Nine GDM women participated in two, 8-day test periods. Each subject ingested one of six prenatal vitamin-mineral preparations, a placebo, or a sucrose capsule, in random order. Blood glucose was determined by the One Touch System at 0, 30, and 60 minutes. The sucrose capsule contained 1 g sucrose (equivalent to highest glucose/carbohydrate content of any prenatal vitamin). The placebo contained 1 g table salt in the same color capsule. Relative glycemic index (RGI, defined as the area under glucose curve for the test substance divided by the area under glucose curve for 1 g sucrose) and maximum rise of blood glucose above time 0 were calculated for each preparation. RGI was significantly elevated for all vitamins: TRN 3.86, Natalins Rx 3.00, Filibon Forte 2.16, Prenatal Formula 2.10, Materna 1.66, Placebo 1.33, Stuartnatal 1 + 1 1.16. Two thousand mg vitamin C (n = 4) resulted in an RGI of 1.37. In conclusion, ingestion of prenatal vitamins produces a rise in blood glucose greater than that seen following ingestion of sucrose equal to the carbohydrate content of prenatal vitamins. The cause of the blood glucose rise is not known, but it would appear prudent to prescribe a prenatal vitamin with a low RGI.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adult
  • Blood Glucose / analysis*
  • Diabetes, Gestational / blood*
  • Female
  • Humans
  • Minerals / administration & dosage
  • Pregnancy
  • Prenatal Care*
  • Regression Analysis
  • Time Factors
  • Vitamins / administration & dosage
  • Vitamins / adverse effects*


  • Blood Glucose
  • Minerals
  • Vitamins