<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2010-10-14</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001022368</issuerCik>
        <issuerName>SCHIFF NUTRITION INTERNATIONAL, INC.</issuerName>
        <issuerTradingSymbol>WNI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001257667</rptOwnerCik>
            <rptOwnerName>HOBART MATTHEW</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TPG CAPITAL, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>301 COMMERCE ST., SUITE 3300</rptOwnerStreet2>
            <rptOwnerCity>FORT WORTH</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>76102</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>No securities are beneficially owned</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Matthew Hobart does not directly own any securities of Schiff Nutrition International, Inc. (the &quot;Issuer&quot;).</footnote>
        <footnote id="F2">Mr. Hobart is a Managing Director of TPG Growth, LLC, which is affiliated with TPG STAR SNI, L.P., a Delaware limited partnership (&quot;TPG STAR SNI&quot;), which, as of the date hereof, directly holds the 7,486,574 shares of Class A Common Stock (the &quot;TPG Stock&quot;) of the Issuer.  Mr. Hobart disclaims beneficial ownership of the shares of TPG Stock that are or may be beneficially owned by TPG STAR SNI or any of its affiliates, including Tarrant Capital Advisors, Inc. Pursuant to Rule 16a-1(a)(4) under the Securities Exchange Act of 1934, as amended (the &quot;Exchange Act&quot;), this filing shall not be deemed an admission that Mr. Hobart is, for purposes of Section 16 of the Exchange Act or otherwise, the beneficial owner of any equity securities of the Issuer directly held by the TPG STAR SNI or any of its affiliates.</footnote>
    </footnotes>

    <remarks>Remarks:

(3) Ronald Cami is signing on behalf of Matthew Hobart pursuant to an authorization and designation letter dated July 1, 2010, which is filed herewith as Exhibit 1.</remarks>

    <ownerSignature>
        <signatureName>/s/ Ronald Cami, on behalf of Matthew Hobart(3)</signatureName>
        <signatureDate>2010-10-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
