Vitamin Therapy in Greenville, SC
Vitamin Therapy at IHP Greenville. Dr. Hendry, DAOM — functional medicine, root-cause diagnostics, personalized care. Call (864) 365-6156.
Oral vitamin C is subject to SVCT transporter saturation above 200 mg — plasma levels plateau regardless of how high the dose goes. IV vitamin C at pharmacological doses achieves plasma concentrations 100 times higher, producing hydrogen peroxide selectively in tissues with low catalase activity. That's not a detail for academic interest — it's the difference between a supplement and a pharmacological intervention. I hold an Injection Therapy certification and use it to deliver B12 intramuscularly in patients with pernicious anemia or terminal ileum resection, where no oral dose on earth gets absorbed. The route of administration determines the clinical effect. I prescribe based on what the physiology of absorption requires, not what's convenient to swallow.
How Vitamin Therapy Works
Vitamin therapy at IHP includes oral supplementation at therapeutic doses (B12 as methylcobalamin or adenosylcobalamin, vitamin D3/K2 combinations, fat-soluble vitamins), and intramuscular injections (B12 IM, B-complex IM, vitamin D IM) for patients requiring rapid repletion or who have absorption impairment from gut conditions. All vitamin therapy is based on documented deficiency or therapeutic indication — not generic wellness supplementation.
Conditions Treated with Vitamin Therapy
IV Vitamin Therapy vs. Oral Supplementation: The Bioavailability Ceiling
Oral supplementation is appropriate for maintaining adequate nutrient status in patients with intact gastrointestinal function and no documented absorption pathology. For the majority of patients, daily oral vitamin D3, B12, and magnesium achieve and sustain target ranges. The clinical indication for IV or injectable administration emerges when the oral route is mechanistically incapable of delivering therapeutic concentrations. Consider a patient with Crohn's disease and terminal ileum resection: the terminal ileum is the exclusive absorption site for B12-intrinsic factor complex. Following resection, no oral B12 dose — regardless of magnitude — can be absorbed through the active transport mechanism; Stabler (NEJM, 2013) documented this pharmacokinetic reality clearly. Monthly intramuscular B12 restores serum cobalamin and resolves megaloblastic anemia within weeks. Similarly, a patient with pancreatic exocrine insufficiency has impaired fat-soluble vitamin absorption across the board — D, E, K, and A — because bile salt-mediated micelle formation is compromised. Oral fat-soluble vitamin supplementation in this context produces unpredictable and typically inadequate plasma responses. Injectable or water-miscible formulations bypass pancreatic and biliary dependence entirely. The decision to use IV or injectable therapy is a mechanistic one grounded in absorption physiology, not a preference for a more intensive intervention.
Research & Evidence
Intravenous and injectable vitamin therapy achieves plasma concentrations of key nutrients that oral administration cannot replicate due to the saturable transport mechanisms governing gastrointestinal absorption. Ascorbic acid (vitamin C) administered orally is subject to sodium-dependent vitamin C transporter (SVCT) saturation: oral doses above approximately 200 mg produce diminishing incremental increases in plasma concentration, with excess excreted renally. IV administration bypasses this ceiling entirely, achieving plasma concentrations of 200-400 mg/dL versus the 1-2 mg/dL ceiling of oral dosing — a 100-fold difference with directly different biochemical outcomes. At supraphysiologic plasma concentrations, ascorbate generates hydrogen peroxide selectively in the extracellular space of tumor tissue (due to differential catalase activity) while supporting collagen hydroxylation and immune cell respiratory burst function. Aranow C (J Investig Med, 2011) documented analogous absorption limitations for vitamin D in patients with fat malabsorption syndromes, where even high oral doses fail to restore 25-hydroxyvitamin D levels without the pharmacokinetic advantage of injectable administration. Stabler SP (N Engl J Med, 2013) established that B12 deficiency secondary to pernicious anemia — autoimmune destruction of intrinsic factor — cannot be corrected by any oral dose due to complete absence of the active absorption mechanism, making injectable B12 the only clinically effective route.
Your First Appointment
Bring all current vitamins and supplements with dosages. A comprehensive nutrient panel to identify true deficiencies is typically ordered before initiating vitamin therapy. Dr. Hendry prescribes evidence-based therapeutic doses — not the minimal RDA amounts found in retail multivitamins.
Why Dr. Hendry for Vitamin Therapy
Dr. Hendry's Injection Therapy certification enables him to administer vitamin injections — including high-dose B12 IM for neuropathy and pernicious anemia, and vitamin D IM for rapid repletion in severely deficient patients.