. 2010 Mar 29;58(8):4632–4637. doi: 10.1021/jf100113c

Table 3. Estimated and Measured ¹⁴C Levels from ¹⁴C-Labeled Nutrients as a Function of Time since Dose.

				α-tocopherol (20)
	unit	β-carotene (18)	lutein (19)	RRR	all-rac	folic acid (21)
dose	nCi	100	36	101.5	99.95	100

estimated maximum ¹⁴C level/mg of C (in 25 μL of plasma)^a
distributed in plasma of 3 L	Modern	137	49	139	137	137
distributed in interstitial water of 18 L	Modern	23	8	23	23	23
distributed in WB water of 42 L	Modern	10	4	10	10	10

measured maximum¹⁴C level/mg of C
plasma	Modern	13	3.8	21	14	4.7 ± 1.6
feces^b	Modern	≥35	54	18	11	53 ± 50
urine^b	Modern	≈ 53	1.0	0.6	1.8	66 ± 22

Assumed 100% absorption of ¹⁴C-nutrient since dose.

Except for feces and urine samples in folic acid study (21), some feces and urine samples (18−21) that were suspected to have high ¹⁴C levels were diluted with a TRIB for optimal ¹⁴C-AMS measurement (0.01−100 Modern range).

Table 3. Estimated and Measured 14C Levels from 14C-Labeled Nutrients as a Function of Time since Dose.

Table 3. Estimated and Measured ¹⁴C Levels from ¹⁴C-Labeled Nutrients as a Function of Time since Dose.