It works within 48 to 72 hours and your body begins to make red blood cells.
In very rare cases, pernicious anemia (caused due to vitamin B12 deficiency) due to malabsorption of vitamin B12 even after consuming meat.
Stomach acids can be treated by having medications which block the acid production. And also by consuming antacids.
Research suggests that iron does help in the absorption of vitamin B12.
Yes one can take them together to ensure the prevention of vitamin B12 deficiency.