The study “investigated the effects of mild and severe vitamin B1 deficiencies on oocyte maturation” in female mice. Poor-quality oocytes with spindle and chromosomal abnormalities are associated with miscarriage and infertility, and high-fat diets contribute to these defects in mice.
The mice were divided into two groups: one was fed a vitamin B1-free diet for 13 days, resulting in mild vitamin B1 deficiency. The other was put on the same diet for 20 days, resulting in severe vitamin B1 deficiency.
It was found that mild vitamin B1 deficiency did not affect oocyte quality, but severe vitamin B1 deficiency led to a higher frequency of abnormal oocytes.
Vitamin B1 deficiency is an area of concern in Japan. The study stated: “Vitamin B1 deficiency can be accelerated by…reasons such as increased energy requirement, the ingestion of raw fish and seafood containing anti-thiamin components”, and chronic alcoholism.
The study also hypothesised that this could lead to miscarriage and infertility, as oocytes need pyruvic acid as a “vital energy source” during meiotic maturation. Pyruvate dehydrogenase (PDH) and its coenzymes, which play important roles in energy production for this process, are in turn dependent on vitamin B1.
It concluded: "Mild vitamin B1 deficiency did not affect the quality of oocytes. On the contrary, severe vitamin B1 deficiency caused an increase in the frequency of abnormal oocytes. However, this frequency was returned to the normal range by refeeding the mice with a vitamin B1–containing diet."
The study, carried out by academics from The University of Shiga Prefecture, added that in light of the different effects of biotin and vitamin B1, “each nutrient has an individual role in oogenesis and meiotic maturation”, and that “the effects of other B-group vitamins such as niacin, pantothenic acid, and folacin on oocyte quality should be investigated”.
Source: Nutrition and Metabolic Insights
“Effects of Mild and Severe Vitamin B Deficiencies on the Meiotic Maturation of Mice Oocytes”
Authors: Ai Tsugi, et al.