Influence of varying vitamin B₆ intake levels on the vitamin B₆ status of fetuses and reproductive organs

In order to study the influence of varying vitamin B₆ intake levels on the reproductive performance and the vitamin B₆ status of fetuses and reproductive organs, 30 pregnant rats (Sprague Dawley strain) were fed a semisynthetic casein diet supplemented with 1,6, 12, 24 and 48 mg vitamin B₆/kg throughout pregnancy. On days 19 of pregnancy the rats were killed. Fetuses, placenta, amniotic fluid, amnion, uterus and mammary gland were analysed microbiologically for their vitamin B₆ content. Reproductive performance was not influenced by the dietary treatment. Vitamin B₆ concentrations in fetuses, placenta and amniotic fluid of mothers treated with the low 1-ppm vitamin B₆ diet were significantly decreased. At a vitamin B₆ supply of 6 ppm, however, tissue saturation was already reached in these organs. Accordingly, the whole vitamin B₆ retention in the reproductive product plateaued at an intake level of 6 ppm vitamin B₆ at 37 μg vitamin B₆ per animal. These results indicate therefore that a level of 6 ppm dietary vitamin B₆ is sufficient to guarantee an optimum vitamin B₆ status in the reproductive product, and higher vitamin B₆ supplementations showed no further effect on the parameters investigated.