Here’s an article about the subject:
A few tidbits:
“Unfortunately, we do not yet know the optimal ratios between these two vitamins, but it is clear that nearly all cod liver oil products supply them in levels that do not appear to be ideal.”
“However, as I began reviewing the latest research, I realized there was compelling evidence that the ratios of these two vitamins may be of paramount importance in order to extract optimal health benefits. And this latest study appears to confirm that theory.
It’s important to understand that vitamin A is essential for your immune system and a precursor to active hormones that regulate the expression of your genes just like vitamin D, and the two work in tandem.
For example, there is evidence that without vitamin D, vitamin A can be ineffective or even toxic. But if you’re deficient in vitamin A, vitamin D cannot function properly either.
So proper balance of these two vitamins is essential. Too much or too little of either may create negative consequences.”
So based on this article, you get confused even more! No one knows the correct ratio of these two vitamins? Why does my naturopath know (supposedly) the correct ratio?