SECTION 1. How citizenship may be lost.—A Filipino citizen may lose his citizenship in any of the following ways and/or events:
By naturalization in a foreign country;
By express renunciation of citizenship;
By subscribing to an oath of allegiance to support the constitution or laws of a foreign country upon attaining twenty-one years of age or more;
By accepting commission in the military, naval or air service of a foreign country;
By cancellation of the certificate of naturalization;
By having been declared, by competent authority, a deserter of the Philippine army, navy or air corps in time of war, unless subsequently a plenary pardon or amnesty has been granted; and
In the case of a woman, upon her marriage to a foreigner if, by virtue of the law in force in her husband's country, she acquires his nationality.