Poor general health and nutrition are two key factors in many older adults' recovery from injuries and hospitalization. Anemia and low folic acid levels often point to a chronic state of poor nutrition. In other words this has been present for a long time.
Folic acid is a synthetic (man made) form of vitamin B that is often added to food or taken as a supplement. B12 vitamin deficiency is another common nutritional problem in older adults. Because of a decline or complete lack of intrinsic factor in older adults, the intestines can't absorb vitamin B12.
A recent study of nutritional and other factors affecting outcomes after hip fracture showed that anemia is linked with poor results of rehab. Blood transfusion early on in rehab may not be soon enough. Low levels of folic acid and serum (blood) albumin are also linked with poor results. Albumin is a type of protein in the blood. Measuring levels of albumin in the blood can be used as an indicator of kidney function.
More studies are being done to find out the best way to treat these deficiencies. Talk to your father's doctor about this. Find out what steps are being taken to correct the nutritional deficiencies. Ask what you can do to help once he is discharged.