Microcytic hypochromic anemia due to inadequate nutrition is best treated with:

Oral iron preparations in the form of ferrous salts (sulfate, fumarate, gluconate) are the preferred and most inexpensive treatments for microcytic, hypochromic (iron deficiency) anemia. The bioavailability of various oral ferrous salts is relatively similar. Ferrous sulfate is less expensive than the other forms however, and should be considered the treatment of choice. Ferric salts show poorer absorption. Macrocytic megaloblastic anemias arise from derangements in DNA metabolism and are symptoms of either vitamin B12 or folate deficiency. Diagnosis of the underlying cause of the anemia must precede the treatment, since folate administration will apparently correct the anemia but allow undetected neurological damage associated with B12 deficiency to progress. Ref: Adamson J.W. (2012). Chapter 103. Iron Deficiency and Other Hypoproliferative Anemias. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.