EX-99.(a)(1)(D)

THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY TIME, AT THE END OF FRIDAY, SEPTEMBER 9, 2016, UNLESS THE OFFER IS EXTENDED OR EARLIER TERMINATED BY THE OFFERORS.

We have been engaged by Fortress Biotech, Inc., a Delaware corporation (“Parent”), and FBIO Acquisition, Inc., a Delaware corporation and a wholly-owned subsidiary of Parent (“Acquisition Sub” and, together with Parent, the “Offerors”), to act as Information Agent (the “Information Agent”) in connection with the Offerors’ offer to purchase all outstanding shares of common stock, par value $0.02 per share (“Shares”), of National Holdings Corporation, a Delaware corporation (the “Company”), at a price of $3.25 per Share, net to the seller in cash (less any required withholding taxes and without interest) (the “Offer Price”) upon the terms and subject to the conditions set forth in the Offer to Purchase, dated August 12, 2016 (together with any amendments or supplements thereto, the “Offer to Purchase”), and in the related Letter of Transmittal (together with any amendments or supplements thereto, the “Letter of Transmittal” and, together with the Offer to Purchase, the “Offer”) enclosed herewith. Please furnish copies of the enclosed materials to those of your clients for whom you hold Shares registered in your name or in the name of your nominee.

The Offer is not subject to any financing condition or any condition regarding any minimum number of Shares being validly tendered in the Offer. The Offer is, however, subject to the satisfaction of other conditions described in the Offer to Purchase. See Section 13 of the Offer to Purchase.

2. Letter of Transmittal for your use in accepting the Offer and tendering Shares and for the consideration of your clients;

3. Notice of Guaranteed Delivery to be used to accept the Offer if certificates for the Shares and all other required documents cannot be delivered to Computershare Trust Company, N.A. (the “Depositary”) by the expiration time of the Offer or if the procedure for book-entry transfer cannot be completed by the expiration time of the Offer;

4. A letter to stockholders of the Company from the Chairman of the Board of the Company, accompanied by the Company’s Solicitation/Recommendation Statement on Schedule 14D-9;

5. A printed letter that may be sent to your clients for whose accounts you hold Shares in your name or in the name of your nominee, with space provided for obtaining such clients’ instructions with regard to the Offer; and

YOUR PROMPT ACTION IS REQUESTED. WE URGE YOU TO CONTACT YOUR CLIENTS AS PROMPTLY AS POSSIBLE. THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY TIME, AT THE END OF FRIDAY, SEPTEMBER 9, 2016, UNLESS THE OFFER IS EXTENDED OR EARLIER TERMINATED BY THE OFFERORS.

The Offer is being made in connection with the Agreement and Plan of Merger, dated as of April 27, 2016, as amended by Amendment No. 1 to Agreement and Plan of Merger, dated as of August 12, 2016 (together with any amendments or supplements thereto, the “Merger Agreement”), among Parent, Acquisition Sub and the Company, pursuant to which, after the completion of the Offer and the satisfaction or waiver of certain conditions, including the Merger Condition (as defined in the Offer to Purchase), Acquisition Sub will be merged with and into the Company, with the Company continuing as the surviving corporation (the “Merger”).

THE BOARD OF DIRECTORS OF THE COMPANY IS REMAINING NEUTRAL AND MAKING NO RECOMMENDATION TO THE HOLDERS OF SHARES AS TO WHETHER TO ACCEPT THE OFFER AND TENDER THEIR SHARES PURSUANT TO THE OFFER.

After careful consideration, the Company’s board of directors (the “Company Board”) based upon the unanimous recommendation of independent review committees of the Company Board, unanimously (a) determined that the Merger Agreement and the transactions contemplated thereby are in the best interests of the Company and its stockholders, and declared it advisable to enter into the Merger Agreement; (b) approved the execution and delivery by the Company of the Merger Agreement, the performance by the Company of its covenants and agreements contained therein and the consummation of the Offer and, if applicable, the Merger upon the terms and subject to the conditions set forth in the Merger Agreement (such approval having been made in accordance with the Delaware General Corporation Law (“DGCL”)); (c) resolved to remain neutral and make no recommendation to the holders of Shares as to whether to accept the Offer and tender their Shares pursuant to the Offer; (d) elected that the Merger contemplated by the Merger Agreement, if any, be expressly governed by Section 251(h) of the DGCL; (e) approved the Offer, the Merger, the Merger Agreement, the Stockholder Rights Agreement (as defined in the Offer to Purchase), the Support Agreement (as defined in the Offer to Purchase), the Voting Agreement (as defined in the Offer to Purchase) and the transactions contemplated thereby for purposes of and in accordance with Section 203 of the DGCL; and (f) adopted certain other resolutions necessary and appropriate to effect such transactions. As soon as practicable following the consummation of the Offer and subject to the satisfaction or waiver of the remaining conditions set forth in the Merger Agreement, including the Merger Condition, Parent, Acquisition Sub and the Company will cause the Merger to become effective without a meeting of the stockholders of the Company to adopt the Merger Agreement in accordance with Section 251(h) of the DGCL.

Upon the terms and subject to the conditions of the Offer (including, if the Offer is extended or amended, the terms and conditions of any such extension or amendment), Acquisition Sub will be deemed to have accepted for payment, and will pay for, all Shares validly tendered in the Offer, and not properly withdrawn, prior to the expiration time of the Offer if and when Acquisition Sub gives oral or written notice to the Depositary of Acquisition Sub’s acceptance of the tender of such Shares for payment pursuant to the Offer. Payment for Shares accepted for payment pursuant to the Offer will be made only after timely receipt by the Depositary of (a) certificates for such Shares or a Book-Entry Confirmation (as defined in the Offer to Purchase) with respect to such Shares pursuant to the procedures set forth in the Offer to Purchase, (b) a Letter of Transmittal (or facsimile thereof) properly completed and duly executed, with any required signature guarantees (or, in the case of a book-entry transfer, an Agent’s Message (as defined in the Offer to Purchase) in lieu of the Letter of Transmittal), and (c) any other documents required by the Letter of Transmittal. Accordingly, tendering stockholders may be paid at different times depending upon when certificates for Shares or Book-Entry Confirmation with respect to Shares are actually received by the Depositary. Under no circumstances will interest be paid on the Offer Price for Shares, regardless of any extension of the Offer or any delay in payment for Shares.

Neither Parent nor Acquisition Sub will pay any fees or commissions to any broker or dealer or other person (other than its financial advisors, the Information Agent and the Depositary as described in the Offer to Purchase)

in connection with the solicitation of tenders of Shares pursuant to the Offer. You will be reimbursed upon request for customary mailing and handling expenses incurred by you in forwarding the enclosed offering materials to your clients. Acquisition Sub will pay all stock transfer taxes applicable to its purchase of Shares pursuant to the Offer, subject to Instruction 6 of the Letter of Transmittal.

If holders of Shares wish to tender their Shares, but it is impracticable for them to deliver their certificates representing tendered Shares or other required documents or to complete the procedures for delivery by book-entry transfer prior to the expiration time of the Offer, a tender may be effected by following the guaranteed delivery procedures specified in the Offer to Purchase and the Letter of Transmittal.

Questions and requests for assistance or for additional copies of the enclosed materials may be directed to us at the address and telephone number set forth below and in the Offer to Purchase. Additional copies of the enclosed materials will be furnished at Acquisition Sub’s expense.

NOTHING CONTAINED HEREIN OR IN THE ENCLOSED DOCUMENTS SHALL RENDER YOU OR ANY PERSON THE AGENT OF THE OFFERORS OR THE COMPANY, THE INFORMATION AGENT, THE DEPOSITARY OR ANY OF THEIR AFFILIATES, OR AUTHORIZE YOU OR ANY OTHER PERSON TO USE ANY DOCUMENT OR MAKE ANY REPRESENTATION ON BEHALF OF ANY OF THEM WITH RESPECT TO THE OFFER NOT CONTAINED IN THE OFFER TO PURCHASE OR THE LETTER OF TRANSMITTAL.