Table 2 Validation scheme for candidate intake biomarkers of dairy products. The questions Q1-Q8 are reported in Additional file 1: Table S10. Possible answers are Y (yes, the criterion is fulfilled for at least some use of the biomarker), N (no, the criterion has been investigated but it was not fulfilled), or U (uncertain, the criterion has not been investigated or data is not available). The questions are based on the criteria of Dragsted et al. [10]

Dairy fat/dairy products

C15:0

HMDB0000826

Blood plasma/serum

Y

U

N

Y

Y

U

Y

Y

C17:0

HMDB0002259

Blood plasma/serum

Y

U

N

Y

Y

U

Y

Y

C17:1

HMDB0060038

Blood serum

Y

U

N

Y

U

U

Y

N

Dairy products

Myristoyl-sphingomyelin SM(d18:1/14:0)

NA

Blood serum

Y

U

N

Y

U

U

U

N

Galactonate

HMDB0000565

Y

U

N

Y

U

U

U

N

Butter

Methyl palmitate

HMDB0061859

Blood serum

Y

U

N

Y

U

U

U

N

Cheese

Isovalerylglutamic acid

HMDB0000726

Urine

Y

U

N

Y

U

U

U

N

Isovalerylglycine

HMDB0000678

Urine

Y

U

N

Y

U

U

U

N

Tiglylglycine

HMDB0000959

Urine

Y

U

N

Y

U

U

U

N

Isobutyrylglycine

HMDB0000730

Urine

Y

U

N

Y

U

U

U

N

Whey protein hydrolysed

Cyclo (Phe-Val)

NA

Blood plasma

N

U

Y

U

U

U

U

U

Cyclo (Ile-Val)/ Cyclo (Leu-Val)

NA

Blood plasma

N

U

Y

U

U

U

U

U

Cyclo (Ala-Ile)

NA

Blood plasma

N

U

Y

U

U

U

U

U

pGlu-Pro

NA

Blood plasma

N

U

Y

U

U

U

U

U

pGlu-Leu

NA

Blood plasma

N

U

Y

U

U

U

U

U

pGlu-Val

NA

Blood plasma

N

U

Y

U

U

U

U

U

Whey protein

γ -glutamyl-leucine

HMDB0011171

Blood plasma

U

U

Y

U

U

U

U

U

γ-glutamyl-valine

HMDB0011172

Blood plasma

U

U

Y

U

U

U

U

U

γ-glutamyl-methionine

HMDB0034367

Blood plasma

U

U

Y

U

U

U

U

U

Casein

Proline-proline

HMDB0011180

Blood plasma

U

U

Y

N

U

U

U

U

Isoleucine-proline

HMDB0011174

Blood plasma

U

U

Y

N

U

U

U

U