Document ID: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-ca13-16-01125/USCOURTS-ca13-16-01125-0/pdf.json

Parties Involved:
Sigma-Tau HealthScience, Inc.
Appellant
United States
Appellee

Document Text:

United States Court of Appeals 

for the Federal Circuit ______________________ 

SIGMA-TAU HEALTHSCIENCE, INC., AKA SIGMATAU HEALTHSCIENCE, LLC,

Plaintiff-Appellant

v.

UNITED STATES,

Defendant-Appellee

______________________ 

2016-1125

______________________ 

Appeal from the United States Court of International 

Trade in No. 1:11-cv-00093-GWC, Judge Gregory W. 

Carman.

______________________ 

Decided: September 26, 2016

______________________ 

JOHN C. MONICA, JR., Porter Wright Morris & Arthur, 

Washington, DC, argued for plaintiff-appellant. Also 

represented by LESLIE ALAN GLICK, CHRISTOPHER YOOK. 

ALEXANDER J. VANDERWEIDE, Commercial Litigation 

Branch, Civil Division, United States Department of 

Justice, New York, NY, argued for defendant-appellee. 

Also represented by AMY M. RUBIN; BENJAMIN C. MIZER, 

JEANNE E. DAVIDSON, Washington, DC; YELENA SLEPAK, 

Office of Assistant Chief Counsel, U.S. Customs and 

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2 SIGMA-TAU HEALTHSCIENCE, INC. v. US

Border Protection, United States Department of Homeland Security, New York, NY.

______________________ 

Before NEWMAN, DYK, and REYNA, Circuit Judges.

DYK, Circuit Judge. 

This Customs case concerns the classification of two 

chemical products, both stabilized forms of the compound

carnitine, which were imported into the United States by 

Sigma-Tau HealthScience, Inc., a.k.a. Sigma-Tau 

HealthScience, LLC (“Sigma-Tau”). United States Customs and Border Protection (“Customs” or “the government”) initially classified these products under a 

subheading of the Harmonized Tariff Schedule of the 

United States (“HTSUS”) that carries a duty. Sigma-Tau 

protested, arguing that the products should be classified 

under HTSUS heading 2936 (which encompasses “provitamins and vitamins”), subheading 2936.29.50, a duty-free 

classification.

The Court of International Trade (“CIT”) concluded 

that Sigma-Tau’s products should be classified under a 

different subheading, 2923.90.00, making them ineligible 

for duty-free treatment. Sigma-Tau HealthScience, Inc. v. 

United States (“Sigma-Tau”), 98 F. Supp. 3d 1365, 1377–

78 (Ct. Int’l Trade 2015). On appeal, the parties agree 

that the only issue is whether Sigma-Tau’s products are 

properly classified as vitamins under HTSUS heading 

2936. We agree with Sigma-Tau that its carnitine products are properly classified under that heading, because 

carnitine is a vitamin in neonates. We therefore reverse 

and remand. 

BACKGROUND

Customs classifications according to the headings and 

subheadings of the HTSUS determine the duties that 

importers must pay to the United States. The question 

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SIGMA-TAU HEALTHSCIENCE, INC. v. US 3

here is the appropriate classification of Sigma-Tau’s 

carnitine products.

Carnitine1 is a naturally occurring amino acid derivative and an important nutrient in the human body, where 

it serves to transport long-chain fatty acids into mitochondria, the centers for energy production within each 

cell. Our bodies obtain carnitine exogenously, from food, 

and also produce it endogenously, by breaking down and 

reforming protein. (According to the Webster Comprehensive Dictionary, an “exogenous” compound originates 

outside the organism, while an “endogenous” compound is 

one originating or produced internally. See Exogenous, 

Webster Comprehensive Dictionary (Int’l ed. 2001); Endogenous, id.) Stabilized forms of carnitine are formulated 

into tablets or capsules and sold as nutritional supplements; they can also be incorporated into drinks, protein 

bars, and other products for human consumption. Carnitine is sometimes referred to as “vitamin Bt”; for example, the online version of Merriam Webster’s Medical 

Dictionary identifies “vitamin Bt” as a synonym of “carnitine.” J.A. 1279. While carnitine is an organic compound, it is not listed by name in any heading or 

subheading of HTSUS Chapter 29, which covers “Organic 

Chemicals.” 

Sigma-Tau imports carnitine products into the United 

States. The two carnitine products at issue are acetyl Lcarnitine taurinate hydrochloride with 1.5% silica, which 

 

1 Carnitine is a chiral compound and exists in two 

distinct stereoisomeric forms: the biologically active Lcarnitine enantiomer and the inactive D-carnitine enantiomer. Sigma-Tau’s products specifically contain Lcarnitine, and the parties agree that L-carnitine is the 

biologically and commercially significant enantiomer at 

issue in this case. For simplicity, we refer hereinafter to 

L-carnitine simply as “carnitine.”

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4 SIGMA-TAU HEALTHSCIENCE, INC. v. US

Sigma-Tau sells under the brand name “L-Tauro,” and 

glycine propionyl L-carnitine hydrochloride USP with 

1.5% silica, which Sigma-Tau sells under the brand name 

“GlycoCarn.” These products, white powders manufactured in Italy, were imported in bulk. In 2010, Customs 

classified these products under HTSUS subheading 

3824.90.92, which covers “Prepared binders for foundry 

molds or cores; chemical products and preparations of the 

chemical or allied industries (including those consisting of 

mixtures of natural products), not elsewhere specified or 

included: Other: Other: Other: Other.” That subheading 

carries a 5% duty. Sigma-Tau timely protested this 

classification, arguing that the products qualify as vitamins under HTSUS subheading 2936.29.50, which covers

“Provitamins and vitamins, natural or reproduced by 

synthesis (including natural concentrates), derivatives 

thereof used primarily as vitamins, and intermixtures of 

the foregoing, whether or not in any solvent: Vitamins 

and their derivatives, unmixed: Other vitamins and their 

derivatives: Other: Other.” That subheading is duty-free.

 Sigma-Tau brought suit in the CIT, requesting that 

the court set aside Customs’ classification decision and

hold that the L-Tauro and GlycoCarn products are properly classified as vitamins under HTSUS subheading

2936.29.50 (and, therefore, deserving of duty-free treatment). Sigma-Tau also requested that the CIT instruct 

Customs to re-liquidate the entries for these products and 

to award damages for alleged overpayment of duties. 

Sigma-Tau moved for summary judgment. The government cross-moved for summary judgment, arguing that 

Customs’ initial classification of the merchandise under 

HTSUS heading 3824 was erroneous but that HTSUS 

subheading 2923.90.00 (covering “Quaternary ammonium 

salts and hydroxides; lecithins and other phosphoaminolipids, whether or not chemically defined: Other”), not 

2936.29.50, was in fact the proper classification.

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SIGMA-TAU HEALTHSCIENCE, INC. v. US 5

The CIT found that Sigma-Tau’s products were prima 

facie classifiable both as vitamins under HTSUS heading 

2936 and as quaternary ammonium salts under heading 

2923. Sigma-Tau, 98 F. Supp. 3d at 1374–76. Where an 

item is prima facie classifiable under more than one 

heading, the General Rules of Interpretation provide 

guidance as to which heading should be used. See Dell 

Prods. LP v. United States, 642 F.3d 1055, 1057 (Fed. Cir. 

2011). Relying on HTSUS General Rule of Interpretation 

3 (“GRI 3”), which specifies that when “goods are, prima 

facie, classifiable under two or more headings” “[t]he 

heading which provides the most specific description shall 

be preferred to headings providing a more general description,” HTSUS, General Notes, at 1, the CIT concluded that “the term ‘quaternary ammonium salts’ more 

specifically describes L-Carnitine than ‘vitamins’” and 

thus that Sigma-Tau’s products were properly classified 

as quaternary ammonium salts under subheading 

2923.90.00, Sigma-Tau, 98 F. Supp. 3d at 1377.

The CIT consequently granted summary judgment in 

favor of the government and denied Sigma-Tau’s motion 

for summary judgment. Id. at 1378. Sigma-Tau appeals, 

asking us to hold that the proper classification of its 

merchandise is under HTSUS subheading 2936.29.50, as 

a vitamin. We have jurisdiction under 28 U.S.C. 

§ 1295(a)(5). 

DISCUSSION

“The interpretation of the headings and subheadings

of the HTSUS is a question of law, which we review 

without deference.” Deckers Corp. v. United States, 532 

F.3d 1312, 1314 (Fed. Cir. 2008); see also Airflow Tech., 

Inc. v. United States, 524 F.3d 1287, 1290 (Fed. Cir. 

2008). “A classification decision involves two underlying 

steps: (1) determining the proper meaning of the tariff 

provisions, which is a question of law; and (2) determining 

which heading the particular merchandise falls within, 

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6 SIGMA-TAU HEALTHSCIENCE, INC. v. US

which is a question of fact.” Deckers, 532 F.3d at 1314–

15. “We review questions of law de novo, including the 

interpretation of the terms of the HTSUS, whereas factual findings of the Court of International Trade are reviewed for clear error.” Id. at 1315; see also La Crosse 

Tech., Ltd. v. United States, 723 F.3d 1353, 1358 (Fed. 

Cir. 2013). However, “if there is no genuine dispute over 

the nature of the merchandise, . . . the proper classification under which it falls [is] the ultimate question in 

every classification case and one that has always been 

treated as a question of law.” Bausch & Lomb, Inc. v. 

United States, 148 F.3d 1363, 1366 (Fed. Cir. 1998); see 

also Gen. Elec. Co.-Med. Sys. Grp. v. United States, 247 

F.3d 1231, 1235 (Fed. Cir. 2001). 

The government concedes that the CIT erred when it 

applied the rule of relative specificity of GRI 3 to classify 

Sigma-Tau’s products. The government acknowledges 

that Note 3 to Chapter 29 of the HTSUS (“Chapter Note 

3”) is instead applicable. Chapter Note 3 specifies that 

“[g]oods which could be included in two or more of the 

headings of this chapter are to be classified in that one of 

those headings which occurs last in numerical order.” 

HTSUS, Ch. 29, Note 3, at 29–1. We have held that “[t]he 

Section and Chapter Notes [of the HTSUS] are not optional interpretive rules, but are statutory law.” BenQ 

Am. Corp. v. United States, 646 F.3d 1371, 1376 (Fed. Cir. 

2011) (internal quotation marks omitted). Consequently, 

if Sigma-Tau’s merchandise is prima facie classifiable as 

both a quaternary ammonium salt (HTSUS heading 2923) 

and as a vitamin (HTSUS heading 2936), Chapter Note 3 

dictates that it be classified as the latter, as 2936 “occurs 

last in numerical order.” 

Thus, the only issue before us is whether Sigma-Tau’s 

L-Tauro and GlycoCarn products are prima facie classifiable as vitamins under HTSUS heading 2936. If they are, 

that heading applies; if they are not, heading 2923 apCase: 16-1125 Document: 41-2 Page: 6 Filed: 09/26/2016
SIGMA-TAU HEALTHSCIENCE, INC. v. US 7

plies, as both sides agree that the products are prima 

facie classifiable as quaternary ammonium salts.2

I 

We first address the government’s contention that the 

products are not vitamins because they contain stabilizers. The two products at issue are stabilized forms of 

carnitine: acetyl L-carnitine taurinate hydrochloride with 

1.5% silica (L-Tauro) and glycine propionyl L-carnitine 

hydrochloride, USP with 1.5% silica (GlycoCarn). The 

CIT treated the products as equivalent to carnitine itself. 

At the CIT, the parties agreed that this was the correct 

approach. “The parties agree that the proper classifica-

 

2 Before the CIT, Sigma-Tau argued that even if 

classified as quaternary ammonium salts under HTSUS 

heading 2923, its L-Tauro and GlycoCarn products should 

nonetheless qualify for “K designation” and thereby be

granted duty-free treatment because “carnitine” is listed 

in the Pharmaceutical Appendix to the HTSUS. “General 

Note 13 [of the HTSUS] permits duty free treatment of 

certain pharmaceutical products if three requirements are 

met . . . .” Forest Labs., Inc. v. United States, 476 F.3d 

877, 882 (Fed. Cir. 2007). One requirement of General 

Note 13 is that “the merchandise is listed in the Pharmaceutical Appendix of the tariff schedule.” Id.

The CIT concluded that while carnitine itself is indeed 

listed in the Pharmaceutical Appendix, the taurine and 

glycine components of L-Tauro and GlycoCarn, respectively, are not listed, making L-Tauro and GlycoCarn ineligible for K designation and thus ineligible for duty-free 

treatment under General Note 13. Sigma-Tau, 98 F. 

Supp. 3d at 1377. Sigma-Tau does not appeal this aspect 

of the CIT’s judgment. The inclusion of carnitine in the 

Pharmaceutical Appendix is unrelated to the question of 

whether carnitine is prima facie classifiable as a “vitamin” under HTSUS heading 2936. 

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8 SIGMA-TAU HEALTHSCIENCE, INC. v. US

tion of the two products at issue hinges upon the primary 

and only active component of the products, L-Carnitine.” 

Sigma-Tau, 98 F. Supp. 3d at 1370. In its briefing at the 

CIT, the government described “L-carnitine (or carnitine)” 

as “the only biologically active component of the two 

products at issue” and indicated that the other chemical

components serve merely as stabilizers, which “render the 

two carnitine-based products at issue chemically neutral 

and stable.” J.A. 336. 

On appeal, the government agrees that carnitine is 

“the sole biologically active component of L-Tauro and 

GlycoCarn” but now argues, apparently for the first time, 

that “the court erred when it undertook a classification 

analysis of L-Carnitine only, and not the actual products 

in their imported condition,” i.e., carnitine combined with 

stabilizing ingredients. Appellee’s Br. at 28. The government does not articulate a theory as to how the presence of any particular stabilizing component of L-Tauro or 

GlycoCarn (e.g., taurine, glycine, or silica) renders the 

products non-vitamins. 

The government’s argument comes too late and is 

therefore waived. “Our precedent generally counsels 

against entertaining arguments not presented to the 

district court.” Golden Bridge Tech., Inc. v. Nokia, Inc., 

527 F.3d 1318, 1322 (Fed. Cir. 2008); see also Singleton v. 

Wulff, 428 U.S. 106, 120 (1976). Furthermore, even if the 

government had properly raised the argument, the 

HTSUS forecloses it. HTSUS heading 2936 explicitly 

encompasses “[p]rovitamins and vitamins” and “derivatives thereof used primarily as vitamins,” and Note 1(f) to 

Chapter 29 of the HTSUS expressly states that the headings of the chapter cover “[compounds] with an added 

stabilizer (including an anticaking agent) necessary for 

their preservation or transport.” HTSUS, Ch. 29, Note 

1(f), at 29–1.

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SIGMA-TAU HEALTHSCIENCE, INC. v. US 9

We thus agree with the CIT that Sigma-Tau’s imported products, L-Tauro and GlycoCarn, should be viewed as 

equivalents of carnitine. The proper classification of 

carnitine itself determines the proper classification of 

Sigma-Tau’s merchandise. 

II

Chapter 29 of the HTSUS covers “Organic Chemicals.” Heading 2936 more specifically covers “Provitamins 

and vitamins, natural or reproduced by synthesis (including natural concentrates), derivatives thereof used primarily as vitamins, and intermixtures of the foregoing, 

whether or not in any solvent.” The terms “carnitine” and 

“vitamin Bt” do not appear anywhere under heading 2936 

or, indeed, anywhere in Chapter 29. Thus, if carnitine is 

classifiable as a vitamin under heading 2936, it must be 

because it falls within a residual subheading, 2936.29.50

(“Vitamins and their derivatives, unmixed: Other vitamins and their derivatives: Other: Other”). 

The CIT construed HTSUS heading 2936 as, in relevant part, an eo nomine provision—i.e., a provision that 

describes an article by a specific name, not by use, see 

Len-Ron Mfg. Co., Inc. v. United States, 334 F.3d 1304, 

1308 (Fed. Cir. 2003). Sigma-Tau, 98 F. Supp. 3d at 

1376–77. We agree with the CIT that HTSUS heading 

2936 should be treated as an eo nomine provision for 

purposes of this case: the operative question here is 

whether carnitine qualifies as a “[p]rovitamin[]” or “vitamin[],” items that are expressly named and covered by 

HTSUS heading 2936.3 Neither party disputes this 

interpretation. Because we conclude that HTSUS head-

 

3 HTSUS heading 2936 also encompasses “derivatives [of provitamins and vitamins] used primarily as 

vitamins”; this separate portion of heading 2936 is properly read as a use provision. 

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10 SIGMA-TAU HEALTHSCIENCE, INC. v. US

ing 2936 is an eo nomine provision with respect to “vitamins,” we need not consider the Carborundum factors, 

which pertain only to certain use provisions of the 

HTSUS. See Aromont USA, Inc. v. United States, 671 

F.3d 1310, 1312–13 (Fed. Cir. 2012); cf. GRK Canada, 

Ltd. v. United States, 761 F.3d 1354, 1358 (Fed. Cir. 

2014). 

“The first step in properly construing a tariff classification term is to determine whether Congress clearly 

defined that term in either the HTSUS or its legislative 

history.” Airflow Tech., 524 F.3d at 1290–91 (quoting 

Russell Stadelman & Co. v. United States, 242 F.3d 1044,

1048 (Fed. Cir. 2001)). In this instance, there is no clear 

definition of “vitamin” within Chapter 29 or its legislative 

history. We have held that, 

[w]hen, as here, a tariff term is not defined in either the HTSUS or its legislative history, the 

term’s correct meaning is its common or dictionary meaning in the absence of evidence to the contrary. We have explained that, to determine the 

common meaning of a tariff term, a court may rely 

upon its own understanding of terms used, and 

may consult standard lexicographic and scientific 

authorities. 

Id. at 1291 (citation, alterations, and internal quotation 

marks omitted). “To discern the common meaning of a 

tariff term, we may consult dictionaries, scientific authorities, and other reliable information sources.” Kahrs Int’l, 

Inc. v. United States, 713 F.3d 640, 644 (Fed. Cir. 2013). 

To the extent that dictionaries or other extrinsic references disagree with one another, a court may “properly 

rel[y] on the definition most commonly found in the 

lexicographical sources to derive the common meaning of 

this term.” Len-Ron, 334 F.3d at 1310. 

Here the CIT’s decision that carnitine is prima facie 

classifiable as a vitamin rested on the fact that carnitine 

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SIGMA-TAU HEALTHSCIENCE, INC. v. US 11

is alternatively known as “vitamin Bt.” “[T]he Court finds 

that since L-Carnitine is commonly known as vitamin Bt 

it is prima facie classifiable in HTSUS heading 2936.” 

Sigma-Tau, 98 F. Supp. 3d at 1376. Similarly, the government argues in support of the opposite result that 

carnitine cannot be a vitamin because many respected 

scientific sources do not include carnitine in listings of 

commonly accepted vitamins. The government notes, for 

example, that a National Import Specialist for Customs 

testified with regard to Sigma-Tau’s carnitine products 

that “the FDA does not indicate they’re vitamins,” nor did 

the scientific literature he had reviewed. J.A. 750. 

Whether a substance is commonly referred to as a 

“vitamin” may be pertinent, but only if there is a consensus as to the use of that terminology. See Len-Ron, 334 

F.3d at 1310 (holding that the common meaning of the 

HTSUS term “vanity case” should not be limited to cases 

that include mirrors, as the record showed that the public 

uses the term to refer to a variety of cases, with no consensus that the term “requires that the case be fitted with 

a mirror”); Nippon Kogaku (USA), Inc. v. United States, 

673 F.2d 380, 382, 384 (CCPA 1982) (holding that a 

certain type of optical microscope should be classified 

under a particular tariff heading because, inter alia, the 

CIT had found that “without contradiction, industry, as 

well as ophthalmologists and optometrists, principal users 

of the merchandise, refer to it as a slit-lamp microscope or 

a slit-lamp, not as a compound microscope”); see also 

CamelBak Prods., LLC v. United States, 649 F.3d 1361, 

1368 (Fed. Cir. 2011) (holding that “how the subject 

articles are regarded in commerce” and “how the subject 

articles are described in sales and marketing literature” 

can “guide the court’s assessment of whether articles fall 

within the scope of an eo nomine provision”). There is no 

such consensus here. We must, therefore, determine 

whether carnitine is a “vitamin” under HTSUS heading 

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12 SIGMA-TAU HEALTHSCIENCE, INC. v. US

2936, applying the commonly accepted definition of the 

term “vitamin.”4 

Indeed, HTSUS heading 2936 contemplates such an 

inquiry. By its very terms the heading covers not only 

approximately one dozen expressly named vitamins5 but 

also open-ended categories of further “Vitamins and their 

derivatives,” including “Other vitamins and their derivatives: Other: Aromatic or modified aromatic” (HTSUS 

subheading 2936.29.20) and “Other vitamins and their 

derivatives: Other: Other” (HTSUS subheading 

2936.29.50). While Explanatory Notes to HTSUS headings are non-binding (see infra), the Explanatory Note to 

heading 2936 states in its “List of products which are to 

be classified as provitamins or vitamins within the mean-

 

4 This is not a case in which Customs or the importer contends that the term in question has a special

commercial meaning distinct from its common meaning. 

See Carl Zeiss, Inc. v. United States, 195 F.3d 1375, 1379

(Fed. Cir. 1999) (“One who argues that a tariff term 

should not be given its common or dictionary meaning 

must prove that it has a different commercial meaning 

that is definite, uniform, and general throughout the 

trade.”); see also Nix v. Hedden, 149 U.S. 304, 306 (1893) 

(“There being no evidence that the words ‘fruit’ and 

‘vegetables’ have acquired any special meaning in trade or 

commerce, they must receive their ordinary meaning.”)

5 The individual vitamins expressly included under 

HTSUS subheading 2936 are vitamin A (2936.21.00), 

vitamin B1 (2936.22.00), vitamin B2 (2936.23.00), D- or 

DL-pantothenic acid (vitamin B3 or vitamin B5, 

2936.24.00), vitamin B6 (2936.25.00), vitamin B12

(2936.26.00), vitamin C (2936.27.00), vitamin E 

(2936.28.00), folic acid (2936.29.10), niacin and niacinamide (2936.29.15), vitamin D (2936.29.50.20), and biotin 

(2936.29.50.30). 

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ing of heading 29.36” that “[t]he list of products in each of 

the following groups is not exhaustive” and that “[t]he 

products listed are examples only.” Explanatory Notes to 

the Harmonized Commodity Description and Coding 

System 29.36 (5th ed. 2012) (“EN 29.36”). Explanatory 

Note 29.36 also includes a list of “Exclusions,” products 

“which, though sometimes called vitamins, have no vitamin activity or have a vitamin activity which is of secondary importance in relation to their other uses” and thus 

are not classifiable under HTSUS 2936. Id. Among the 

excluded products are various compounds whose names 

include the word “vitamin,” such as “Vitamin H1,” “Vitamin B4,” and “Vitamin F.” Id. (Carnitine (or vitamin Bt) 

is not included among the “Exclusions.” Id.) The note 

thus makes clear that the mere use of the term “vitamin” 

to refer to a particular compound is not conclusive. At the 

same time, the universe of compounds prima facie classifiable as vitamins under heading 2936 cannot be limited 

to only those compounds that are explicitly listed under 

the heading. 

We thus look to the definition of “vitamin” and ask 

whether carnitine falls within the definition. “Determining the proper classification requires first construing the 

relevant provisions of the schedule and then deciding 

which provision encompasses the merchandise at issue.” 

Del Monte Corp. v. United States, 730 F.3d 1352, 1354 

(Fed. Cir. 2013); see also Airflow Tech., 524 F.3d at 1291. 

Before the CIT, the government urged that the court

apply the definition of “vitamin” in the Explanatory Note: 

Vitamins are active agents, usually of complex 

chemical composition, which are obtained from 

outside sources and are essential for the proper 

functioning of human or other animal organisms. 

They cannot be synthesised by the human body

and must therefore be obtained in final or nearly 

final form (provitamins) from outside sources. 

They are effective in relatively minute amounts 

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14 SIGMA-TAU HEALTHSCIENCE, INC. v. US

and may be regarded as exogenous biocatalysts, 

their absence or deficiency giving rise to metabolic 

disturbances or “deficiency diseases.” 

EN 29.36 (emphasis added). The government contended 

at the CIT that because carnitine can be synthesized in 

the human body, it is not a vitamin under the definition of 

EN 29.36. But Explanatory Notes are not Chapter Notes 

or Section Notes and are not binding. Explanatory Notes 

“may be generally useful as guides to the scope of unclear 

HTSUS headings, [but] they are not legally binding.” 

Archer Daniels Midland Co. v. United States, 561 F.3d 

1308, 1315 (Fed. Cir. 2009) (internal quotation marks 

omitted); see also E.T. Horn Co. v. United States, 367 F.3d 

1326, 1329 (Fed. Cir. 2004) (Explanatory Notes are “not 

controlling” but “provide interpretive guidance”). “Although the examples in the Explanatory Notes are probative and sometimes illuminating, we shall not employ 

their limiting characteristics, to the extent there are any, 

to narrow the language of the classification heading 

itself.” Rubie’s Costume Co. v. United States, 337 F.3d 

1350, 1359 (Fed. Cir. 2003). 

Explanatory Note 29.36, in defining vitamins as compounds that “cannot be synthesised by the human body,” 

cannot be correct, since vitamin D is unambiguously 

included under the heading: subheading 2936.29.50.20

expressly names “Vitamins D and their derivatives.” And 

undisputed evidence establishes that vitamin D can be

synthesized, in limited and generally inadequate

amounts, by the human body. See Sigma-Tau, 98 F. 

Supp. 3d at 1375–76. This portion of the definition of 

“vitamin” in EN 29.36 thus contradicts the express inclusion of vitamin D under HTSUS heading 2936 and must 

be disregarded, as the CIT correctly held. Id. at 1376. 

Explanatory Note 29.36 is also inconsistent with the 

prevailing definitions of “vitamin” in various scientific 

references cited by the parties, all of which define a 

vitamin as a compound that is not produced by the human 

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SIGMA-TAU HEALTHSCIENCE, INC. v. US 15

body in amounts “sufficient” or “adequate” for healthy 

function.6 The parties indeed agree that the definition of 

 

6 The definitions of “vitamin” presented by the parties are as follows. Sigma-Tau’s expert submitted a report 

presenting definitions from two textbooks: 

(From The Vitamins:) A vitamin: (i) is an organic 

compound distinct from fats, carbohydrates, and 

proteins; (ii) is a natural component of foods in 

which it is usually present in minute amounts; 

(iii) is essential, usually in minute amounts, for 

normal physiological function (i.e., maintenance, 

growth, development, and/or production); 

(iv) causes, by its absence or underutilization, a 

specific deficiency syndrome; and (v) is not synthesized by the host in amounts adequate to meet 

normal physiological needs. 

(From Nutrition Now:) Vitamins are chemical 

substances that perform specific functions in the 

body. They are essential nutrients because, in 

general, the body cannot produce them or [cannot] 

produce sufficient amounts of them. 

J.A. 288 (Expert Report of Yesu T. Das, quoting Gerald F. 

Combs, Jr., The Vitamins 4 (4th ed. 2012) (J.A. 291) and 

Judith E. Brown, Nutrition Now 20–2 (7th ed. 2014) (J.A. 

292)) (alteration and emphasis in original, underscoring 

added). 

The government introduced definitions from two 

chemical encyclopedias:

Vitamins are specific organic compounds that are 

essential for normal metabolism. These micronutrients are not synthesized by humans, either at all 

or in sufficient quantity, and must be obtained 

from the diet or as synthetic supplements.

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16 SIGMA-TAU HEALTHSCIENCE, INC. v. US

EN 29.36 is too restrictive in this respect. For example,

the government proposes defining “vitamins” as “those 

organic compounds which are essential for human health, 

but must be provided or supplemented from an exogenous 

source because the human body cannot normally synthesize the compounds, either sufficiently or at all.” Appellee’s Br. at 14 (emphasis added). Moreover, the 

definitions provided by both parties are consistent with 

each other. We therefore adopt, as the definition of “vitamin,” the following: vitamins are organic chemical 

substances that are essential micronutrients because, in 

general, the body cannot produce them or produce sufficient amounts of them. 

While agreeing to this general definition, the parties 

still differ as to the proper scope of this definition in 

certain respects. First, Sigma-Tau argues that “vitamin” 

should not be limited to compounds that are required by 

individuals with normal function but should also encompass those required by individuals with abnormal function. We reject this argument. Literature definitions 

introduced by both parties emphasize the fact that a 

vitamin is a substance required for normal physiological 

 

J.A. 778 (reproducing the Concise Encyclopedia of Chem. 

Tech. 2092 (4th ed. 1999)) (emphasis added).

Vitamins are essential, organic compounds which 

are either not synthesized in the human and animal organism or formed only in insufficient 

amounts. Therefore, they must be regularly consumed with the diet either as such or as a precursor (provitamin) that can be converted to the 

vitamin in the body. . . . Vitamins are classified 

not chemically but by their activity.

J.A. 780 (reproducing Ullmann’s Encyclopedia of Indus. 

Chemistry vol. 38, 112 (6th ed. 2003)) (emphasis added). 

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SIGMA-TAU HEALTHSCIENCE, INC. v. US 17

function. See J.A. 291 (The Vitamins: “essential . . . for 

normal physiological function”; “not synthesized by the 

host in amounts adequate to meet normal physiological 

needs” (emphasis added)); J.A. 292 (Nutrition Now: “essential nutrients because, in general, the body cannot 

produce them or produce sufficient amounts of them” 

(emphasis added)); J.A. 778 (Concise Encyclopedia of 

Chem. Tech.: “specific organic compounds that are essential for normal metabolism” (emphasis added)). The 

correct definition of “vitamin” thus leaves out compounds 

that might be essential to individuals with abnormal 

physiological function, e.g., those suffering from rare 

genetic disorders or organ failure. 

Second, the government appears to argue that the 

proper definition of “vitamin” refers only to compounds 

that cannot be synthesized in sufficient amounts by 

human adults. On the contrary, Sigma-Tau argues that 

the proper definition of “vitamin” must not be limited to 

compounds essential to adults but should also include 

compounds that children and infants require for normal, 

healthy function. We agree with Sigma-Tau that there is 

no reason to limit “vitamin” to compounds required by 

adults rather than children. Neither the definition of EN 

29.36 nor any of the literature definitions presented by 

either party is expressly limited to adults. Moreover, the 

definition in The Vitamins describes “vitamins” as compounds “essential” for “maintenance, growth, development, and/or production,” J.A. 291 (emphasis added); the 

inclusion of “growth” and “development” suggests that 

compounds required by children—i.e., those who are 

“growing” and “developing”—should be included even if 

not required by adults.

III 

Having defined “vitamin,” we turn to whether carnitine is prima facie classifiable as such under HTSUS 

heading 2936. We hold, based on the undisputed evidence 

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18 SIGMA-TAU HEALTHSCIENCE, INC. v. US

of record, that the CIT’s conclusion on this point was 

correct: carnitine is prima facie classifiable as a vitamin. 

Sigma-Tau argues that the evidence shows that “certain human populations, including children and neonates, 

require an exogenous source of L-Carnitine.” Appellant’s 

Reply Br. at 14. Sigma-Tau introduced uncontroverted 

evidence establishing that infants, including neonates 

(infants less than four weeks old), require exogenous 

sources of carnitine for healthy growth and cannot synthesize adequate quantities endogenously. One scientific

article states that “[n]eonates rely on an exogenous supply 

of L-carnitine because their capacity for endogenous 

synthesis is still poorly developed.” J.A. 1089 (J. 

Harmeyer, The Physiological Role of L-Carnitine, 27 

Lohmann Info. 1, 7 (2002)). A second article states that 

“certain pediatric populations, specifically neonates and 

infants, have decreased biosynthetic capacity and are at 

risk of developing carnitine deficiency, particularly when 

receiving PN [(parenteral nutrition)]” and that 

“[a]lthough carnitine is considered a nonessential nutrient 

in adults, it may be considered a conditionally essential 

nutrient in pediatric populations, particularly neonates 

receiving PN.” J.A. 1091, 1094 (Catherine M. Crill & 

Richard A. Helms, The Use of Carnitine in Pediatric 

Nutrition, 22 Nutrition in Clinical Practice 204, 207 

(2007)). 

The scientific authorities cited by the government do 

not directly address the question of whether carnitine 

qualifies as a vitamin with respect to infants. They

merely state that carnitine is not recognized as a vitamin 

in adults, as adults are able to synthesize adequate quantities of carnitine from other components of their diet. 

For example, the book Recommended Dietary Allowances, 

a publication of the National Research Council introduced 

by the government, states that “[carnitine] has not been 

demonstrated to be a vitamin for the healthy adult human” but adds that “the newborn infant appears to have 

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SIGMA-TAU HEALTHSCIENCE, INC. v. US 19

reduced stores of carnitine as well as a low capacity for 

synthesizing it” and that “[s]everal laboratories are investigating the possibility that carnitine may be an essential 

nutrient for the newborn, especially for those born prematurely.” J.A. 789, 790 (Recommended Dietary Allowances

265, 266 (10th ed. 1989)). At argument the government 

conceded that the evidence shows that infants, and neonates in particular, require exogenous sources of carnitine 

for normal, healthy function. 

In view of this evidence, the CIT correctly held that

carnitine is prima facie classifiable as a vitamin. Undisputed evidence in the record shows that carnitine is an 

organic compound essential for neonates (infants less 

than four weeks old). They rely on an exogenous supply of 

L-carnitine because their ability to synthesize it endogenously is still poorly developed. 

CONCLUSION

For the foregoing reasons, carnitine and Sigma-Tau’s 

imported merchandise are prima facie classifiable as a 

vitamin under HTSUS heading 2936. As noted above, 

under Chapter Note 3, “[g]oods which could be included in 

two or more of the headings of this chapter are to be 

classified in that one of those headings which occurs last 

in numerical order.” We thus hold that carnitine, and 

Sigma-Tau’s products, are properly classified as a vitamin 

under HTSUS heading 2936, in residual subheading 

2936.29.50, rather than as a quaternary ammonium salt 

under HTSUS heading 2923. We conclude that the CIT 

erred in denying Sigma-Tau’s motion for summary judgment and in granting summary judgment to the government. We reverse and remand for further proceedings 

consistent with this opinion.

REVERSED AND REMANDED 

COSTS

No costs.

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