Results and Discussion

For each subject,

Conversion efficiency factor =

Total amount of 2H-β-carotene ingested x 548 (nmol)
--------------------------------------------------------------------------------
Total amount of 2H-retinol in total serum x 291 (nmol)

Results

Average amount of 2H-retinol in total serum in 8 subjects = 72.9 nmol
Mean conversion factor = 3.2 ± 1.5 to 1 (by weight)

This means that for every 3.2mg of β-carotene we consume from the biofortified yellow maize, we get 1mg of retinol (Vitamin A).

Discussion

US Recommended Dietary Allowances for VITAMIN A:

Adult MALES	900ug
Adult FEMALES	700ug
CHILDREN	400ug

Zimbabweans consume about 330g of maize sadza per person per day (staple food). Since a 300g dose of biofortified yellow maize sadza comprises about 1.2mg of β-carotene, 330g of the biofortified yellow maize sadza would provide 1.32mg of β-carotene, translating to 412.5ug of Vitamin A. This fulfills about 45.8% of an adult male's daily Vitamin A needs.

This is certainly an improvement from the situation at present, in which the average intake of Vitamin A per capita per day in Zimbabwe stands at just 211ug (less than a quarter of recommended daily intake). 

• Good conversion factor observed in the study could be due to:

1. Milling of biofortified yellow maize kernels into flour
2. Eating sadza together with butter and corn oil
3. Presence of α-Tocopherol antioxidants 

•  Local Zimbabweans need to be educated to replace traditionally eaten WHITE MAIZE with BIOFORTIFIED YELLOW MAIZE