The following question was posed:
Are the amount of vitamins the same on all this different trees? And are all safe to use?
Emphasis mine. Should questions on what plants are safe to use be on-topic on Sustainable Living?
I realize that a desire to live a sustainable, resource-neutral life is closely correlated with using natural resources to keep us healthy and nourished.
I am married to someone with a keen interest in nutrition and what uses natural resources (plants, fungi, etc) can be used for when it comes to our health. As such, I am very much aware that there are serious risks involved with using plants you are not familiar with; mistake hemlock for parsley and you will fall seriously ill or even die.
I fear that if we choose to leave such questions on the site, we are going to end up with a situation where someone falls ill because an answer here had given the impression that a given plant was safe to use, or where the specific plant had not been identified clearly enough. When it comes to funghi, the risks of misidentification are higher still.
For the above example, yes, so far as we know all pines are safe, but you also must be absolutely clear that yew (taxus baccata) is not a pine and not safe to use. A novice could be easily confused if details like that were omitted from an answer.