Cell-study, in vitro, short-term "helping":
Retinoic acid enhances progesterone production via the cAMP/PKA signaling pathway in immature rat granulosa cells
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5616100/
"Our results demonstrated that atRA enhanced progesterone production by upregulating the levels of steroidogenic acute regulatory protein (StAR) and cytochrome P450scc (Cyp11a1) mRNAs, but not 3β-hydroxysteroid dehydrogenase mRNA in immature rat GCs."
On to the real-world, in vivo, longer-term destruction of the same thing:
Testosterone and progesterone level alterations in the adult rat after retinoid (retinol or retinoic acid) treatment (imprinting) in neonatal or adolescent age.
https://www.ncbi.nlm.nih.gov/pubmed/9761376
"Newborn rats were treated with a single dose of vitamin A (retinol), or with three doses of retinoic acid (in the 1st, 3rd and 5th days). Serum testosterone and progesterone level was measured in the four months old male and female rats, respectively. Retinol significantly decreased both hormone levels, however retinoic acid decreased the progesterone level only."
Human study:
Sex hormone patterns and serum retinol concentrations in adolescent girls.
https://www.ncbi.nlm.nih.gov/pubmed/14976795
"During the follicular phase, serum retinol was associated negatively with progesterone."
Translation: More retinol (aka Poison/"Vitamin A") equals less progesterone.
The examples will keep coming.
Cell-study, in vitro, short-term "helping":
Retinoic acid enhances progesterone production via the cAMP/PKA signaling pathway in immature rat granulosa cells
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5616100/
"Our results demonstrated that atRA enhanced progesterone production by upregulating the levels of steroidogenic acute regulatory protein (StAR) and cytochrome P450scc (Cyp11a1) mRNAs, but not 3β-hydroxysteroid dehydrogenase mRNA in immature rat GCs."
On to the real-world, in vivo, longer-term destruction of the same thing:
Testosterone and progesterone level alterations in the adult rat after retinoid (retinol or retinoic acid) treatment (imprinting) in neonatal or adolescent age.
https://www.ncbi.nlm.nih.gov/pubmed/9761376
"Newborn rats were treated with a single dose of vitamin A (retinol), or with three doses of retinoic acid (in the 1st, 3rd and 5th days). Serum testosterone and progesterone level was measured in the four months old male and female rats, respectively. Retinol significantly decreased both hormone levels, however retinoic acid decreased the progesterone level only."
Human study:
Sex hormone patterns and serum retinol concentrations in adolescent girls.
https://www.ncbi.nlm.nih.gov/pubmed/14976795
"During the follicular phase, serum retinol was associated negatively with progesterone."
Translation: More retinol (aka Poison/"Vitamin A") equals less progesterone.
The examples will keep coming.
