I suggest you read this carefully..................
"Fasting for only one week will increase the number of red cells in an anemic person. Medical and laboratory experimenters have conducted all their experiments on healthy men and animals, hence they have not been permitted to observe the regenerating effects of fasting upon the blood. Their statement that "human blood is relatively resistant during fasting" is true, but it does not tell the whole truth. Their statement that "there is a tendency to increase in the red cell count" is also true, but even this does not tell the whole truth.
That the body possesses considerable iron reserve, even in pernicious anemia, is shown by the great and rapid blood regeneration and great increase in hemoglobin and red cells during a fast in these cases. During the fast, the iron liberated by the breaking down of tissue is retained in the body and is not thrown away. Considerable iron and proportionately other necessary elements are consumed during the fast, although the body stores much of its iron in the spleen, liver, marrow cells and in the increased number of red blood cells"......................... http://www.soilandhealth.org/02/0201hyglibcat/020127shelton.III/020127.ch7.htm
In other words it is totally safe to fast with iron-deficiency and is remedial, but you must rest throughout.
The problem lies with absorption rather than a lack of iron in the diet and where fasting will correct this.
Only fast for 7 to 10 days though, where the red-blood cell count will have increased sufficiently for your diet to take over.
I would discontinue with your iron supplements while fasting as they are going to be of no benefit: in fact could be the opposite.