I forgot about Spirulina when I wrote my first post on this thread!
On an empty stomach, if you are tired, you will actually feel yourself sit up straighter and eyes focus after drinking some good spirulina. Tablets don't have so much bang. If you don't mind the taste (I learned to like it) then you can even add SSKI to Spirulina which is naturally high in B vitamins, minerals, iodide, amino acids....