Checking nutrition balance

Question

I've just started to explore nutrition. I assume that:
a1) A human body needs some minerals and vitamins, which can be delivered either in food or as supplements
a2) There's recommended daily amount of each mineral for an average-case healthy human.

What I'd like to know now, without digging deep into each topic:
1) Can a blood test show whether an amount of minerals and vitamins in my body is good for me? Do I need additional tests (bones? etc)?
2) Say, a blood test can show nutrition balance only for today. And I want to know if my nutrition-rich food is digested well. Can a blood test show me if my yesterday's diet was good? Or are that results weaker or not-actual?

I am interested in any opinion with proof-links.
Thanks in advance.

Answer 1

1) Blood tests alone can, in most cases, reveal if your nutritional status is normal or not. If the results are normal and you have no symptoms of disease, there are usually no other tests needed. Only when you are deficient in certain nutrients, other tests may be needed: blood hemoglobin in iron deficiency, bone scanning in calcium deficiency, etc.

2) Blood tests can still show normal vitamin/mineral status after a week or two of complete fasting (drinking only water) or, in case of vitamin A, B12, D or E, even after months or years of insufficient intake, because these nutrients can be obtained from your body stores.