Antiorbital Calcium in Chronic Conditions

Inclusion criteria: * Adults 55-75 years of age * Active diagnosis of one of the following conditions: * Stage 1 Hypertension with Non-valvular Atrial Fibrillation (AF) - including paroxysmal, persistent, or long-standing persistent AF with typical electrocardiographic characteristics (i.e., absence of identifiable p-waves with irregularly irregular ventricular rate) without known complications, heart disease, or congenital heart defects (e.g., rapid ventricular rate, recent myocardial infarction, heart failure, stroke, cardiomyopathy, etc.), self-reported but previously diagnosed by a healthcare professional; * Stage 1 Hypertension (systolic blood pressure of 130-139, diastolic blood pressure of 80-89), self-reported but previously diagnosed by a healthcare professional; * or, Osteoarthritis, self-reported but previously diagnosed by a healthcare professional. * If diagnosed with AF, a European Heart Rhythm Association (EHRA) score of 2b or greater (i.e. Normal daily activity not affected by symptoms related to AF, but patient troubled by symptoms). * On a stable dose of all medications prior to study entry (i.e., consistent dose for a minimum of three months) * Willing to be randomized to take daily ionized calcium as a dietary supplement or placebo over the 24-week study period * On a stable dose of dietary supplements for at least one month prior to enrollment * Willing to avoid initiation of new supplements and/or medications unless otherwise indicated by a healthcare professional * Willing to have blood drawn on 6 occasions, and fast for 10-12 hours before blood draws, over the study period * Willing to have desktop ultrasound of wrist done on 3 occasions. * Able to communicate via email, complete computer-administered questionnaires, and to read and write in English. * Must be able to provide written informed consent * Non-smokers (including tobacco and cannabis products, combusted or vaporized) * Approved to be eligible for study participation at the discretion of the Principal Investigators, after review of the Formal Eligibility Screen results. * Willing to avoid taking dietary supplements containing the following ingredients for the 24 weeks of study involvement: additional supplemental calcium in any form, vitamin D, vitamin K, selenium, magnesium, or zinc. Exclusion criteria: * Individuals with a current or past diagnosis of permanent AF * Individuals with any thyroid or parathyroid disorders, or current use of thyroid medication for any reason. * Individuals with chronic kidney or liver disease, cancer, colorectal disease, and "other rare disorders". * Individuals with a current diagnosis of Congestive Heart Failure (CHF). * Individuals with a current or past diagnosis of Traumatic Brain Injury (TBI), thromboembolism, or Cerebrovascular Accident (CVA)/Stroke. * Use of dihydropyridine or non-dihydropyridine calcium channel blockers for any reason * If diagnosed with atrial fibrillation, not on a stable dose of anti-coagulant or anti-platelet prescription medications (i.e., consistent dose for a minimum of three months) * Abnormalities in coagulation studies (e.g., INR ≤ 2 or ≥ 3.0) or hypercalcemia at the clinical screening visit. * Blood pressure ≥ 140/90 mmHg at the clinical screening visit. * Current involvement or within 14 days prior to screening of a significant diet or weight loss program (such as NutriSystem, Jenny Craig, Atkin's or other low-carb diet programs) or very low-calorie liquid diet programs (such as Optifast, Medifast, and/or HMR) * Hospitalization (for any reason other than a scheduled medical procedure unrelated to atrial fibrillation, hypertension, or osteoarthritis) within 3 months prior to screening * Cardiac surgery within 3 months prior to screening * Malignancy within the last 5 years (with the exception of basal cell carcinoma, squamous cell carcinoma, and/or carcinoma in situ of the cervix) * Are allergic to corn. * Women who are lactating, pregnant or planning pregnancy within the next six months * Intake of ≥ 2 standardized alcohol-containing beverages per day, 14 per week, or ≥4 in any single day within the past 14 days. * Women who experience menstrual periods, who are sexually active and are unwilling to use an appropriate form of contraception during the duration of the trial. * Smoking tobacco or nicotine products (combusted or vaporized) * Use of illicit drugs/substances (such as but not limited to cocaine, phencyclidine (PCP), and methamphetamine) within 14 days of screening * Currently participating in another interventional research study, or participated in another interventional research study within 14 days of screening * Do not have an active primary care provider or specialist (i.e., cardiologist, rheumatologist, orthopedist, etc.) managing their atrial fibrillation, hypertension, or osteoarthritis. * Current use of: dietary supplements or medications utilized for chelation purposes (i.e., ethylenediaminetetraacetic acid; EDTA), or of chemotherapeutic agents. * MoCA score of 16 or less upon screening.