Most adult Americans have health check-ups including blood drawn to assay for anemia or diabetes, but almost never for  iron, transcobalamin II B12 (TC II B12) (holo TC II) or folate, even though these 3 assays are more often abnormal, and more often trigger effective therapy.  Making them part of routine screening will sharply reduce ethnic disparities in health, allowing corrective therapy to prevent genotype (genetic predisposition) from becoming phenotype (disease), protecting millions from early morbidity and mortality.  One in 8 of all Americans, and 1 in 3 African-Americans daily absorb too much dietary iron (i.e. have genetic hemochromatosis [GH]). This GH frequency coincides with greater frequency of diabetes, heart disease, and cancer in African-Americans.  People with GH suffer insidiously progressive multiple-organ damage (diabetes from pancreas iron, cardiomyopathy and arrhythmias from heart iron, cirrhosis and cancer from liver iron, etc). This is prevented by getting rid of the accumulating extra iron by phlebotomy (giving a unit of blood) 3-4 time/yr (V Herbert. Blood 11/99). Caution: Contrary to buzzword antioxidant  claims, vitamin C pills of 100 mg or more, taken daily by 30% of Americans, drive free radical generation from iron, promoting cancer and fatal cardiac arrhythmias in GH (V Herbert. Ann Int Med, Sept. 1999).  High serum homocysteine (Hcy) is associated with vasculo-and neuro-toxicity.  Most high Hcy results from deficiency of B12 and/or folate and/or B6.  Premenopausal black women have higher Hcy, lower folate, and 2-3-fold  more coronary artery disease (CAD) than white women (Gerhard et al. AJCN 1999; 70:252). When a gene for gastric atrophy is expressed (in the fertile years in black females [V Herbert, 1999. EDITORIAL: http://www.harrisonsonline.com]) and somewhere between age 50 and age 90 in almost everybody else) one can no longer absorb food B12. Within a week of no absorption of B12, blood serum holo TC II, a circulating protein which delivers B12 to surface receptors of all DNA-synthesizing cells, becomes low, diagnosing that B12 is no longer being absorbed and gut, blood and nerve cells are becoming deficient.  Misleadingly, total serum B12 remains normal.  Jacques et al found (NEJM 1999;340:1449) that, while fortification of grains with PGA (folic acid) in elderly adults increased serum folate and decreased serum Hcy, the difference in mean Hcy was largely due to differences in use of B vitamin supplements. This supported our studies that, by age 65, 49% of healthy elderly had low holo TC II, 60% of this 49% had high serum Hcy (>17), and supplementation with100mg of crystalline B12 orally daily normalized holoTC II and Hcy (V Herbert. Blood 11/99).  Low folate in elderly may be largely B12 deficiency gut damage causing malabsorption of folate (and B6), corrected by B12 therapy.  A 5-yr delay in heart disease onset will save $69 billion/yr (J. Davis, Letter, NY Times, 8/11/99). We petitioned RHW FDA to require addition of B12 to all folate fortification or supplementation; Surg Gen Satcher agrees. National Institute on Aging's Dr. Longo supports our recommendation that all Americans take 100 mcg daily oral crystalline B12 starting at age 50. Black females should start at age 25 (for the reason stated above).