Can I Take Vitamin D with Leqvio (Inclisiran)?

Why There Is No Interaction Between Inclisiran and Vitamin D

Inclisiran and vitamin D occupy entirely separate metabolic pathways. Their mechanisms do not overlap at any clinically meaningful point, which is why the FDA prescribing information for Leqvio lists no supplement contraindications and no vitamin D warnings [1].

How Inclisiran Works

Inclisiran is a small interfering RNA (siRNA) conjugated to triantennary N-acetylgalactosamine (GalNAc). After subcutaneous injection, the GalNAc moiety directs the molecule to asialoglycoprotein receptors on hepatocytes. Once inside the cell, the siRNA strand binds to PCSK9 messenger RNA and triggers its degradation through the RNA-induced silencing complex (RISC) [2]. This reduces PCSK9 protein production, which allows more LDL receptors to recycle to the hepatocyte surface and clear LDL-C from the bloodstream. The ORION-10 trial (N=1,561) demonstrated a 52.3% placebo-adjusted reduction in LDL-C at day 510 with inclisiran 284 mg [3].

How Vitamin D Is Metabolized

Vitamin D3 (cholecalciferol) undergoes 25-hydroxylation in the liver primarily via CYP2R1, producing 25-hydroxyvitamin D (calcidiol). A second hydroxylation step occurs in the kidneys via CYP27B1, yielding the active hormone 1,25-dihydroxyvitamin D (calcitriol) [4]. These enzymes are distinct from the CYP3A4 and CYP2C9 pathways that drive most drug-supplement interactions. Inclisiran bypasses the cytochrome P450 system entirely because it is degraded by intracellular nucleases, not oxidized by liver enzymes [1].

Why Overlap Is Absent

A pharmacokinetic interaction requires shared transporters, shared metabolizing enzymes, or competitive protein binding. Inclisiran uses receptor-mediated endocytosis via GalNAc-ASGPR. Vitamin D circulates bound to vitamin D-binding protein (DBP) and is hydroxylated by CYP2R1/CYP27B1. There is no common transporter, no shared enzyme, and no overlapping binding site. The Novartis clinical pharmacology program for inclisiran tested coadministration with atorvastatin (a CYP3A4 substrate) and found no interaction [1]. Vitamin D, which does not even use CYP3A4 as its primary pathway, poses an even lower theoretical risk.

Vitamin D Deficiency Is Common in People Taking Leqvio

Patients prescribed Leqvio carry diagnoses of atherosclerotic cardiovascular disease (ASCVD) or heterozygous familial hypercholesterolemia (HeFH). These populations overlap heavily with groups at elevated risk for vitamin D insufficiency.

Prevalence Data

A National Health and Nutrition Examination Survey (NHANES) analysis found that 41.6% of U.S. Adults had serum 25(OH)D levels below 20 ng/mL, with rates reaching 82.1% among non-Hispanic Black adults and 69.2% among Hispanic adults [5]. Age, obesity (BMI ≥ 30), and statin use are all associated with lower vitamin D status [6]. Because Leqvio is typically added to maximally tolerated statin therapy, many patients on inclisiran are already in a subgroup where deficiency is more likely.

Why Correcting Deficiency Matters

The Endocrine Society's 2024 clinical practice guideline recommends empiric vitamin D supplementation of 1,000 to 2,000 IU daily for adults aged 50 and older, adults with high BMI, and adults with darker skin pigmentation, without requiring a baseline 25(OH)D level [7]. The VITAL trial (N=25,871) did not show a statistically significant reduction in major cardiovascular events with 2,000 IU/day vitamin D3 over 5.3 years (HR 0.97, 95% CI 0.85 to 1.12) [8]. Observational data, though, consistently link 25(OH)D levels below 20 ng/mL with increased cardiovascular mortality [9]. Correcting frank deficiency remains standard practice for bone, muscle, and immune health regardless of the cardiovascular signal.

What the Clinical Trial Data Show

The ORION clinical program enrolled over 3,600 patients across ORION-9, ORION-10, and ORION-11. None of these trials excluded patients taking vitamin D supplements, and none reported vitamin D as a source of adverse events or reduced efficacy [3][10][11].

ORION-10 and ORION-11 Details

ORION-10 enrolled 1,561 adults with ASCVD and LDL-C ≥ 70 mg/dL on maximally tolerated statin therapy. ORION-11 enrolled 1,617 adults with ASCVD or ASCVD risk equivalents. Both trials allowed concomitant medications including over-the-counter supplements. The pooled safety analysis reported injection-site reactions (8.2% inclisiran vs. 1.8% placebo) as the most common adverse event. No supplement-related safety signals emerged [3][10].

Post-Marketing Surveillance

The FDA approved Leqvio in December 2021. Through the FDA Adverse Event Reporting System (FAERS), no case reports have linked vitamin D coadministration to altered inclisiran efficacy or unexpected adverse effects as of early 2026 [12]. The European Medicines Agency (EMA) assessment report similarly contains no vitamin D interaction warnings [13].

Pharmacokinetic vs. Pharmacodynamic: Breaking Down the Non-Interaction

Understanding why two agents do or do not interact requires examining both pharmacokinetic (PK) and pharmacodynamic (PD) dimensions. With inclisiran and vitamin D, neither dimension produces a signal.

Pharmacokinetic Assessment

Inclisiran reaches peak plasma concentration approximately 4 hours after subcutaneous injection. It is taken up by hepatocytes through ASGPR-mediated endocytosis, not intestinal absorption. Vitamin D3 is absorbed in the small intestine with dietary fat and transported via chylomicrons to the liver [4]. These absorption, distribution, metabolism, and excretion (ADME) profiles do not intersect. Inclisiran is not a substrate, inhibitor, or inducer of any known CYP enzyme, P-glycoprotein, or organic anion transporter [1].

Pharmacodynamic Assessment

Inclisiran lowers LDL-C by reducing intracellular PCSK9 protein. Vitamin D acts on the vitamin D receptor (VDR), a nuclear receptor that regulates calcium homeostasis, immune modulation, and gene transcription. Some preclinical data suggest VDR activation may modestly influence hepatic lipid metabolism, but no human trial has demonstrated that vitamin D supplementation alters LDL-C in a magnitude that would interfere with PCSK9-targeted therapy [14]. A meta-analysis of 41 randomized controlled trials (N=3,434) found that vitamin D supplementation reduced LDL-C by a non-significant 1.9 mg/dL [14]. That effect size is clinically irrelevant next to inclisiran's 50%+ LDL-C reduction.

Monitoring Recommendations When Taking Both

No special monitoring protocol is required for patients taking vitamin D alongside Leqvio. Standard care already covers the relevant labs.

Lipid Panel

The ACC/AHA guideline recommends checking a fasting lipid panel 4 to 12 weeks after starting or adjusting lipid-lowering therapy, then every 3 to 12 months [15]. For inclisiran, checking LDL-C before the second injection (at 3 months) and before subsequent injections (every 6 months) provides adequate surveillance.

25-Hydroxyvitamin D Level

The Endocrine Society recommends against routine population screening for vitamin D deficiency but supports testing in individuals at increased risk, including those with obesity, malabsorption, chronic kidney disease, or those taking medications that accelerate vitamin D catabolism (such as phenytoin or rifampin) [7]. A baseline 25(OH)D level is reasonable in patients starting Leqvio simply because the ASCVD population carries multiple deficiency risk factors.

Calcium and Parathyroid Hormone

If a patient is taking high-dose vitamin D (above 4,000 IU/day) or has chronic kidney disease, monitoring serum calcium and intact PTH helps avoid hypercalcemia. This is standard vitamin D safety monitoring and has nothing to do with inclisiran [7].

Dose Separation: Not Required

Some drug-supplement pairs require staggered dosing. Levothyroxine and calcium, for example, should be separated by 4 hours because calcium can bind thyroid hormone in the gut and reduce absorption [16]. That scenario does not apply here.

Inclisiran is injected subcutaneously by a healthcare provider. It never enters the gastrointestinal tract. Vitamin D is taken orally. Their absorption routes do not overlap. Even if a patient takes a vitamin D capsule on the same day as their Leqvio injection, neither agent will affect the other's bioavailability. There is no need to adjust timing.

Vitamin D Dosing Guidance for ASCVD Patients

Patients on Leqvio should follow the same vitamin D recommendations as any adult with cardiovascular disease.

Standard Supplementation

For adults aged 19 to 70, the Institute of Medicine (now the National Academies) recommends a dietary allowance of 600 IU/day, rising to 800 IU/day after age 70 [17]. The Endocrine Society's 2024 guideline suggests 1,000 to 2,000 IU/day for adults over 50 and those with elevated BMI, without requiring a serum level first [7].

Treating Documented Deficiency

When 25(OH)D is below 20 ng/mL, a common repletion protocol is 50,000 IU of ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3) weekly for 6 to 8 weeks, followed by a maintenance dose of 1,000 to 2,000 IU daily [18]. This protocol is unaffected by concurrent inclisiran use.

Upper Limits

The tolerable upper intake level for vitamin D is 4,000 IU/day for adults, per the National Academies [17]. Doses exceeding this threshold increase the risk of hypercalcemia and should only be used under clinical supervision with periodic calcium monitoring.

What to Tell Your Prescriber

If you are starting Leqvio and already take vitamin D, no changes are needed. Inform your prescriber of the supplement for completeness. Three points worth discussing:

Your current vitamin D dose. Most adults do well on 1,000 to 2,000 IU daily. If you are taking 5,000 IU or more, your prescriber may want to check a serum calcium level.

Your last 25(OH)D result. If you have never been tested and carry risk factors for deficiency (limited sun exposure, BMI above 30, darker skin pigmentation, age over 65), a one-time baseline level helps guide dosing.

Other supplements you take. While vitamin D does not interact with inclisiran, other supplements (such as red yeast rice, which contains monacolin K, a lovastatin analog) could complicate lipid management. A full supplement review at the time of Leqvio initiation is good practice.

Statin Coadministration Context

Most Leqvio patients are also on a statin. Statins and vitamin D share a relevant intersection that deserves a brief mention.

Statins and Vitamin D Metabolism

Some observational studies have reported that statin use is associated with modest increases in serum 25(OH)D levels, possibly through inhibition of 7-dehydrocholesterol reductase (DHCR7), which shunts more precursor toward the vitamin D synthesis pathway [19]. The clinical significance of this effect is unclear. It does not change vitamin D dosing recommendations.

Muscle Symptoms

Both statin therapy and severe vitamin D deficiency can cause myalgia. In patients reporting muscle pain on a statin-inclisiran regimen, checking 25(OH)D is a simple step that may identify a correctable contributor. A small randomized trial (N=150) found that vitamin D repletion in deficient patients reduced statin-associated muscle symptoms by 33% compared to placebo [20]. Addressing deficiency before attributing symptoms to the statin alone is reasonable.

Patients who maintain 25(OH)D levels above 30 ng/mL and continue both their statin and Leqvio injections on schedule achieve the best LDL-C outcomes without unnecessary therapy interruptions.