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  <element name="AdditionalLicenseFeesReceivableUponAchievementOfCertainMilestones" id="naii_AdditionalLicenseFeesReceivableUponAchievementOfCertainMilestones" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AdditionalLicenseFeesUponAchievementOfCertainMilestones" id="naii_AdditionalLicenseFeesUponAchievementOfCertainMilestones" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AmendedLineOfCreditFacilityMember" id="naii_AmendedLineOfCreditFacilityMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="AmendmentMember" id="naii_AmendmentMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="BankOfAmericaMember" id="naii_BankOfAmericaMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="BrandedProductsMember" id="naii_BrandedProductsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CashPaidDuringPeriodForAbstract" id="naii_CashPaidDuringPeriodForAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ChangeInUnrealizedGainLossOnDerivatives" id="naii_ChangeInUnrealizedGainLossOnDerivatives" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CurrentAccountLoansMember" id="naii_CurrentAccountLoansMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CustomerOneMember" id="naii_CustomerOneMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CustomerThreeMember" id="naii_CustomerThreeMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="CustomerTwoMember" id="naii_CustomerTwoMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DebtInstrumentBasisSpreadOnElectedFixedRateBorrowing" id="naii_DebtInstrumentBasisSpreadOnElectedFixedRateBorrowing" type="num:percentItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DebtPrePaymentPenalty" id="naii_DebtPrePaymentPenalty" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DebtPrepaymentPenaltyRate" id="naii_DebtPrepaymentPenaltyRate" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DerivativeSettlementMonthAndYear" id="naii_DerivativeSettlementMonthAndYear" type="xbrli:gYearMonthItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="DocumentAndEntityInformationAbstract" id="naii_DocumentAndEntityInformationAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EarningsPerShareDisclosureLineItems" id="naii_EarningsPerShareDisclosureLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="EarningsPerShareDisclosureTable" id="naii_EarningsPerShareDisclosureTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="FixedLoansMember" id="naii_FixedLoansMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="ForeignExchangeFacilityMember" id="naii_ForeignExchangeFacilityMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IncomeTaxesLineItems" id="naii_IncomeTaxesLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="IncomeTaxesTable" id="naii_IncomeTaxesTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="LegalProceedingsLineItems" id="naii_LegalProceedingsLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LegalProceedingsTable" id="naii_LegalProceedingsTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="LineOfCreditCovenantNumberOfConsecutiveDaysThatOutstandingBalanceMustBeZero" id="naii_LineOfCreditCovenantNumberOfConsecutiveDaysThatOutstandingBalanceMustBeZero" type="xbrli:durationItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LineOfCreditFacilityMaximumAmountOutstandingAfterReduction" id="naii_LineOfCreditFacilityMaximumAmountOutstandingAfterReduction" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LineOfCreditFacilityMaximumBorrowingCapacityAnnualReduction" id="naii_LineOfCreditFacilityMaximumBorrowingCapacityAnnualReduction" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="LineOfCreditFacilityOutstandingDailyBalanceDuringPeriod" id="naii_LineOfCreditFacilityOutstandingDailyBalanceDuringPeriod" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="MinimumPrepaymentAmountUnderLineOfCredit" id="naii_MinimumPrepaymentAmountUnderLineOfCredit" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NaturalAlternativesInternationalEuropeSaMember" id="naii_NaturalAlternativesInternationalEuropeSaMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NetIncomeRequiredInFutureForIncomeCovenant" id="naii_NetIncomeRequiredInFutureForIncomeCovenant" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfInstallmentPayments" id="naii_NumberOfInstallmentPayments" type="xbrli:decimalItemType" abstract="false" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfPatentsInLawsuit" id="naii_NumberOfPatentsInLawsuit" type="xbrli:decimalItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="NumberOfYearsCompensationUsedForBenefitObligationAssumptions" id="naii_NumberOfYearsCompensationUsedForBenefitObligationAssumptions" type="xbrli:durationItemType" abstract="false" xbrli:periodType="instant" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="OmnibusStockIncentivePlanTwentyZeroNineMember" id="naii_OmnibusStockIncentivePlanTwentyZeroNineMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItems" id="naii_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTable" id="naii_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="OutsideUnitedStatesMember" id="naii_OutsideUnitedStatesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PatentAndTrademarkLicensingMember" id="naii_PatentAndTrademarkLicensingMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PriorToAmendmentMember" id="naii_PriorToAmendmentMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="PrivateLabelContractManufacturingMember" id="naii_PrivateLabelContractManufacturingMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="RoyaltyAndLicensingRevenue" id="naii_RoyaltyAndLicensingRevenue" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="StockholdersEquityNoteLineItems" id="naii_StockholdersEquityNoteLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="StockholdersEquityNoteTable" id="naii_StockholdersEquityNoteTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrldt:hypercubeItem"/>
  <element name="UncategorizedAbstract" id="naii_UncategorizedAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" id="naii_WeightedAverageNumberBasicAndDilutedSharesOutstandingAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
  <element name="WellsFargoMember" id="naii_WellsFargoMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" substitutionGroup="xbrli:item"/>
</schema>
