As your Psych was the one who was urging you to get the bloods done, I'd expect that they are eliminating any physical causes/need for additional treatment with a view to referring you on.
If you are malnourished, there are vitamins that you desperately need that are given when a blood test shows the levels of deficiency make them necessary - in my area, for example, vitamin D can only be given in injection form when the serum levels are incredibly low, is only prescribed as high dose tablets when very low and the rest of the time, will not be funded and you'll be told to buy the normal OTC ones - but you're supposed to also have additional blood tests afterwards to check for other deficiencies being masked. Vitamin D deficiency can also cause MH symptoms, as can B deficiencies, and both can cause serious (as in lifethreatening) conditions if left undiagnosed/untreated.
Anaemia is potentially deadly, as is vitamin C deficiency, osteoporosis can lead to fatal fractures, pain, deformity, etc, too.
If any of those things are present, the Psych will have the information needed to make a referral or to instigate additional treatment. But they can't assume and make a referral beforehand.