Data sources

DRI as published by the Food and Nutrition Board, Institute of Medicine, National Academies

USDA Database version SR24

Details on SR24 measurements used here:

Calorie conversion to grams
For conversion from gram to calorie this site is using a multiplier of 9 for fat, 4 for carbohydrate or protein, and 6.93 for alcohol.
Vitamin A
RAE values (the most recent standard that adjusts for bioavailability) are being used
Vitamin D
The sum of D2 and D3
Vitamin E
The naturally occurring form (RRR-α-tocopherol). Added vitamin E data is ignored.
Vitamin K
The USDA gives vitamin K1 data. K2 MK-4 data is given. Although the DRI focuses on K1, this site used K1 + K2. The USDA does not give data for K2 MK-7. There is also another form present in hydrogenated oils (dihydrophylloquinone) that the USDA gives data for- but this is ignored.
The USDA gives 2 measurements: B-12 and B-12 added. Only B-12 is being used.
Folate / Folic acid
There are 4 data points given by the USDA. There are 2 folate measurements- folate and folic acid. Folic acid is principly a supplement used to enrich grains. USDA also gives total folate and total folate DFE, where the DFE measurement includes folic acide and adjusts for its bioavailibility. The total folate DFE measurement is the one being used.
The total choline value is used- this includes several types of choline, but not betaine.