Is it dangerous to take spirulina with a multivitamin?

Take only MVI's: Spirulina, a microscopic blue- green algae in warm waters is rich in vitamins b1, b2 ; b3. It contains 4 g protein/ tablespoon, useful for vegetarians. A german study in "toxicology and applied pharmacology" 2011, found in all 13 commercially distributed products cytotoxins. Spirulina absorbs heavy metals (hg ;pb) from the environment ; also contains hepatotoxic microcystins. It can cause gout.

Yes: Spirulina is an algae supplement used for fishes and poultry. I assume you are neither. There are complications for eating too much spirulina. Multivitamins are worthless. If you have a tested proven vitamin deficiency, then take that vitamin only. When taken together, there are more chances of metal overdose. Save your money and buy a gym membership for real benefits.