Vitamin B-Complex Injection

Vitamin B-Complex Injection is a sterile compounded solution of essential B vitamins formulated for intramuscular (IM) subcutaneous (SQ) or slow intravenous (IV) use. Each 1 mL contains 100 mg vitamin B₁ (thiamine HCl), 2 mg vitamin B₂ (riboflavin-5′-phosphate sodium), 100 mg vitamin B₃ (niacinamide), 2 mg vitamin B₅ (dexpanthenol), and 2 mg vitamin B₆ (pyridoxine HCl).^[1]

It is prepared in a 30 mL multi-dose vial with a preservative (2% benzyl alcohol) for multiple withdrawals. This injection is typically prescribed to potentially prevent or treat deficiencies of these B vitamins and to support patients with conditions like malabsorption, increased metabolic demand, or recovery from illness where oral vitamin intake is insufficient.^[1]

As a compounded product, it is not an FDA-approved commercially manufactured drug.

B-complex vitamins serve as coenzymes or precursors in numerous biochemical reactions, and together they work synergistically to support metabolism, neurological function, and cellular energy production.^[3]

Thiamine (vitamin B₁) is required for carbohydrate metabolism; in its active form (thiamine diphosphate), it is an essential cofactor for enzymes in glucose and amino acid catabolism, helping convert nutrients into ATP and supporting normal neuronal function.^[3]

Riboflavin (vitamin B₂) is a component of coenzymes FMN and FAD, which drive oxidative energy production and cellular respiration; B₂ is crucial for the metabolism of fats, drugs, and steroids and for the activation of other vitamins (it helps convert vitamin B₆ to its active form and aids the conversion of tryptophan to niacin). ^[4]

Niacinamide (vitamin B₃) forms the coenzymes NAD⁺ and NADP⁺, which are involved in hundreds of oxidation-reduction reactions in cells. These reactions are central to ATP generation, DNA repair, and cell signaling, so adequate B₃ supports energy levels and normal cell function.^[5]

Pantothenic acid (vitamin B₅, provided as dexpanthenol) is a building block of coenzyme A, a critical coenzyme in the Krebs cycle and fatty acid oxidation; through CoA, vitamin B₅ participates in the synthesis of neurotransmitters, steroid hormones, and other key cellular components.^[5]

Pyridoxine (vitamin B₆) is converted to pyridoxal-5′-phosphate, a coenzyme for over 100 enzymes in amino acid metabolism. B₆ is needed for the production of neurotransmitters such as GABA, serotonin, and dopamine, and for glycogen breakdown and hemoglobin synthesis.^[5]

By simultaneously providing all these B vitamins, the injection ensures that the body has all necessary co-factors in adequate supply; this prevents metabolic bottlenecks that might occur if one B vitamin is lacking.

In essence, each component supports different steps of metabolic pathways – for example, energy generation from carbohydrates and fats requires B₁, B₂, B₃, and B₅ in sequence – thereby the combined administration helps optimize overall metabolism and neurological health.^[3]

Patients with deficiencies often experience fatigue, cognitive or nerve impairments, and slow recovery; correcting those deficiencies with the B-Complex Injection can restore normal enzymatic function and improve cellular energy production, which supports vitality and organ function in those individuals.

Vitamin B-Complex Injection should not be used in patients with known hypersensitivity to any of its ingredients. This includes allergy to thiamine or any other B vitamin in the formulation, or to excipients like benzyl alcohol.^[1]

Because the vial contains benzyl alcohol as a preservative, it is contraindicated in neonates and infants – benzyl alcohol has been associated with serious adverse events (the “gasping syndrome”) in newborns and must be avoided in this population.^[6]

Patients with a history of severe allergic reactions to similar injectable vitamins should not receive this product, or should undergo desensitization under close medical supervision if the therapy is deemed essential.

High-dose niacin therapy is normally contraindicated in individuals with active peptic ulcer disease or active liver disease; similarly, while the niacinamide in this compounded B-Complex is in a moderate dose, caution is advised in patients with untreated peptic ulcers or significant hepatic impairment, as even moderate niacin supplementation could aggravate these conditions (e.g. by increasing stomach acidity or liver enzyme elevations).^[7]

Use is also contraindicated in patients with arterial bleeding.^[7] Niacin can cause vasodilation, so it should be avoided in those with serious hypotension; indeed, people with very low blood pressure or those prone to orthostatic hypotension should not use niacinamide injections without careful monitoring.^[8]

Similarly, patients with gout or hyperuricemia should avoid high niacin intake, as niacin (even in nicotinamide form) can raise uric acid levels and potentially trigger gout flares.^[8]

Although not an absolute contraindication, patients with coronary artery disease or unstable angina should only use B-Complex injections containing niacinamide under physician supervision, since high-dose niacin supplements have been linked to arrhythmias in such patients.^[8]

Each individual B vitamin is water-soluble and generally very safe at physiologic doses, but the combination product should only be used when clearly needed.

In summary, this compounded injection is contraindicated in anyone with allergies to its components, in neonates, and in patients in whom even moderate doses of B₃/B₆ might pose unacceptable risks (e.g. active ulcer, serious liver disease, hypotension, or gout).

Because this formulation provides multiple B vitamins at significant doses, it is important to consider how each component might interact with medications or other supplements the patient is taking.

Pyridoxine (B₆) in high doses is known to interact with certain drugs: it can reduce the therapeutic efficacy of levodopa by increasing peripheral conversion of levodopa to dopamine (vitamin B₆ speeds up decarboxylation). For this reason, patients with Parkinson’s disease on levodopa therapy should avoid high B₆ intake unless they are also taking carbidopa (which prevents this interaction). Doses of pyridoxine as low as 5–10 mg can antagonize levodopa’s effect if carbidopa is not present, so caution is warranted and any supplemental B₆ beyond the nutritional dose should be under medical guidance.

Vitamin B₆ can also decrease serum levels of certain anticonvulsant medications; co-administration of pyridoxine has been shown to reduce the blood levels of phenobarbital and phenytoin, possibly diminishing their anticonvulsant efficacy. Patients on those medications should only receive B-Complex injections with close monitoring (and dosage adjustments of the anticonvulsant if needed).

On the other hand, several drugs can deplete pyridoxine or heighten its requirement – for example, isoniazid, cycloserine, penicillamine, and hydralazine each form complexes with B₆ or otherwise interfere with B₆ metabolism, potentially leading to deficiency and peripheral neuropathy. Such patients often are prescribed supplemental B₆; the B-Complex Injection can help mitigate drug-induced B₆ deficiency, but the clinician should be mindful to coordinate its use so that adequate B₆ is maintained without causing excessive levels.

Niacinamide (B₃), like niacin, has several notable interactions. Niacin/niacinamide may potentiate the effects of antihypertensive medications by causing additional vasodilation – if a patient is on blood pressure-lowering drugs (such as beta blockers, alpha-1 blockers, or vasodilators), niacinamide injections could lead to an additive drop in blood pressure. Careful monitoring of blood pressure is recommended when initiating therapy in hypertensive patients, and those with baseline low blood pressure should use B₃-containing injections cautiously.

Niacin can also have an antagonistic effect on gout medications: it elevates uric acid levels, which may counteract drugs like allopurinol or pegloticase that are meant to lower uric acid. Patients being treated for gout should therefore be monitored for changes in uric acid if receiving high-dose B₃; any gout flare-ups might necessitate re-evaluation of niacinamide therapy.

Additionally, niacin has been noted to increase fasting blood glucose by inducing insulin resistance in some cases; large doses might diminish the effectiveness of antidiabetic medications (like insulin, metformin, or sulfonylureas). Although the 100 mg of niacinamide in this injection is relatively modest compared to gram doses used to treat cholesterol, diabetic patients should still have their blood sugar observed, as even moderate niacinamide supplementation could necessitate small adjustments in diabetes medications.

Conversely, isoniazid and pyrazinamide (tuberculosis drugs) are structural analogs of niacin that can interfere with niacin metabolism, potentially precipitating pellagra in rare cases; such patients may require niacin supplementation, which this injection could provide.^[5]

Thiamine (B₁) has no known major drug-drug interactions in terms of altering other medications’ efficacy. However, it’s worth noting that certain diuretics (e.g. furosemide) can increase urinary excretion of thiamine and thereby lower B₁ levels over time. Patients on long-term loop diuretics might benefit from B₁ supplementation, and the B-Complex Injection can help replete thiamine in those individuals.

Chemotherapy with drugs like 5-fluorouracil has also been associated with acute thiamine deficiency by disrupting thiamine activation, so oncology patients receiving such therapy might receive parenteral thiamine supplementation as part of this B-Complex if needed. These are more considerations of medications affecting vitamin status (rather than the vitamin affecting the medication), but they illustrate the clinical judgment required when co-administering this injection with certain treatments.

Riboflavin (B₂) and pantothenic acid (B₅) have fewer documented interactions. One moderate interaction to note is that oral B-complex vitamins, including riboflavin, can interfere with the absorption of tetracycline antibiotics if taken simultaneously. This is not an issue with an injection (since IM/IV bypasses the gut), but if a patient is also taking oral supplements, they should separate them from tetracycline dosing.

High doses of pantothenic acid have been reported to compete with biotin uptake in the intestines (because they share a transport mechanism); again, this is relevant mainly for oral supplementation, but it suggests caution in patients taking separate high-dose biotin supplements.^[5]

Finally, combining this B-Complex Injection with other supplements containing the same vitamins (such as multivitamins or energy drinks) should be done carefully. While toxicity is rare, excessive intake of certain B vitamins (particularly B₃ or B₆) from multiple sources could increase the risk of side effects (like niacin flush or peripheral neuropathy). Patients should inform their healthcare provider of all supplements they use.

In summary, the key interactions to consider are pyridoxine’s reduction of levodopa and anticonvulsant efficacy, niacinamide’s additive effects on blood pressure, blood sugar, and gout management, and the potential need for B-vitamin repletion in patients on certain medications (diuretics, isoniazid, etc.). Close monitoring and consultation with a pharmacist or provider is advised to manage these interactions and adjust therapy as needed.

At recommended dosages, Vitamin B-Complex Injection is well tolerated by most patients, but as with any parenteral therapy, side effects can occur. Injection-site reactions are among the most commonly reported side effects: patients may experience pain, stinging, or mild burning at the IM injection site.^[1] This discomfort is usually transient and can be minimized by using proper technique and allowing the solution to come to room temperature before injection. Some individuals develop a small area of redness or swelling at the injection site after IM administration; this local reaction typically resolves on its own within a day or two.

If the injection is given IV (slowly), there may be a brief sensation of warmth or a mild flushing during the infusion, owing to the niacinamide component – however, unlike nicotinic acid, niacinamide does not usually cause the intense flushing reaction (redness/itching) of the skin. In fact, the chemical form in this product was chosen to avoid that side effect; skin flushing is far less common with nicotinamide than with niacin (nicotinic acid).^[9]

Because B vitamins are water-soluble, excess amounts are excreted in urine, which can lead to a noticeable change in urine color. It is normal for urine to turn a bright yellow-orange color after B-complex injection; this is due to riboflavin and its metabolites, and it is a harmless effect. Patients should be counseled that neon yellow urine is expected – it simply indicates the body is eliminating surplus riboflavin and does not signify any problem.^[4]

Some individuals might experience mild diarrhea or gastrointestinal upset after parenteral B-vitamin administration.^[1] Niacinamide in high doses can sometimes cause nausea, heartburn, or a sensation of warmth; in the 100 mg dose present here, serious GI effects are uncommon, but mild nausea or stomach discomfort could occur in sensitive patients.^[9] Transient itching or rash has been noted in some cases, possibly indicating a mild sensitivity reaction.^[1] If a rash or generalized itching develops, the injection should be halted and the patient evaluated, as it could be a prodrome of a more serious reaction.

Serious adverse effects are rare but have been reported, particularly with IV administration of thiamine. Anaphylactic reactions to thiamine are exceedingly uncommon (estimated incidence well below 1%), but they have been documented. Parenteral thiamine can in rare instances trigger an acute allergic response characterized by hypotension, breathlessness, itching, and swelling; for this reason, some clinicians recommend an intradermal test dose in individuals who may be at risk of thiamine allergy.^[1]

If during injection a patient experiences chest pain, difficulty breathing, hives, or swelling of the face or throat, it could indicate anaphylactic shock – this is a medical emergency requiring immediate intervention (epinephrine, etc.). Fortunately, such reactions are extremely infrequent; a recent safety analysis found no anaphylaxis in hundreds of patients receiving high-dose IV thiamine, suggesting the risk is very low in practice.^[5] Nevertheless, any signs of hypersensitivity (such as a diffuse rash, wheezing, or feeling of throat tightness) warrant stopping the injection and seeking prompt medical care.^[1]

Other rare side effects noted (mostly in older literature or high-dose use) include: polycythemia vera and peripheral vascular thrombosis in patients receiving repeated injections (though these associations are not well understood, they were listed in prior product literature as possible adverse events).^[1] These are exceedingly uncommon and possibly coincidental findings.

Vitamin B₆ (pyridoxine), when chronically taken in gram quantities, is known to cause a sensory neuropathy – numbness and tingling in the extremities – but the amount of B₆ in this formula (2 mg per mL) is far below such neurotoxic levels.^[5] There is essentially no risk of B₆-induced neuropathy at the doses used here, especially given the limited duration most patients use injectable therapy.

Similarly, although hepatic dysfunction can occur with large niacin doses (1–3 grams daily over months) causing elevated liver enzymes or jaundice, niacinamide at 100 mg is very unlikely to have any adverse effect on the liver. To put it in context, nicotinamide has shown signs of liver toxicity only at doses around 3,000 mg per day or higher – many times the total amount a patient would receive weekly from this injection.^[9]

Overall, the safety profile of Vitamin B-Complex Injection is favorable. The most common patient complaints are minor: soreness at injection site, a transient headache, or mild diarrhea – and these tend to resolve quickly. Patients should be advised about the urine discoloration (to avoid alarm) and counseled to report any persistent side effects. If side effects like stomach upset or flushing are bothersome, the dosing schedule might be adjusted (e.g. smaller doses given more frequently).

In clinical use, significant side effects are uncommon, and the vast majority of patients tolerate the therapy without problems. All serious or unexpected adverse reactions (especially allergic responses) should be reported and the therapy re-evaluated. Ensuring proper administration technique (IM deep into muscle, or IV slowly diluted) also helps minimize adverse effects like injection pain or vein irritation.

Pregnant and breastfeeding individuals have increased requirements for many B vitamins, and indeed these vitamins are routinely included in prenatal supplements. All the components of Vitamin B-Complex Injection are essential nutrients for normal fetal development and maternal health. For example, the thiamine requirement rises during pregnancy to about 1.4 mg/day (vs. 1.1 mg in nonpregnant women) and riboflavin likewise increases to 1.4 mg/day.^[4] Deficiency of B vitamins in pregnancy can lead to serious complications – severe thiamine deficiency, while rare, can cause Wernicke’s encephalopathy in hyperemesis gravidarum, and inadequate B₆ is associated with anemia and neurologic issues in the newborn. Therefore, maintaining sufficient levels is important. However, because this product provides doses far above the daily nutritional requirements (for instance 100 mg of B₁ vs an RDA of ~1.4 mg), its use in pregnancy must be carefully considered.

Thiamine (B₁) is generally recognized as safe in pregnancy and is in fact critical to prevent deficiency in pregnant patients with prolonged vomiting. Thiamine has not been associated with fetal harm; pregnant women often receive IV thiamine if needed (e.g., for hyperemesis) without issue. Pyridoxine (B₆) is notably used during pregnancy to treat nausea and vomiting – the combination of vitamin B₆ and doxylamine is an FDA-approved remedy for morning sickness. Pyridoxine is categorized as pregnancy category A, meaning controlled studies have shown no risk to the fetus. This indicates that vitamin B₆ at therapeutic doses is very safe in pregnancy. In fact, adequate B₆ can improve pregnancy outcomes, and deficiency is common if supplementation is not given. Riboflavin (B₂) and pantothenic acid (B₅) have no known teratogenic effects; they are routine constituents of prenatal vitamins and are considered safe when used at recommended doses. No specific pregnancy classification exists for riboflavin or pantothenate in the U.S. (the FDA has exempted many vitamins from formal categorization), but they are regarded as safe as part of a normal diet and necessary for fetal growth.

Niacinamide (B₃) in high pharmacological doses has less pregnancy data. Niacin (nicotinic acid) has been classified as pregnancy category C – meaning that animal studies have shown some adverse effect or there are no well-controlled studies in humans, but potential benefits may warrant use despite potential risks.^[9] High-dose niacin (used to treat cholesterol) lacks human safety data in pregnancy and could theoretically affect the fetus (for example, by causing hypotension or altering lipid metabolism). However, niacinamide at physiological doses (like those in prenatal vitamins or moderate supplements) is not known to be harmful. The 100 mg niacinamide in this injection is higher than the RDA (18 mg NE in pregnancy) but still far below levels used in lipid therapy. If needed for a clear medical indication (such as treating pellagra in a pregnant patient), niacinamide can be used with caution, but unnecessary high-dose B₃ supplementation is avoided in pregnancy.

Given these considerations, Vitamin B-Complex Injection should be used during pregnancy only if clearly indicated. If a pregnant patient has a documented deficiency of one or more B vitamins or a condition like hyperemesis that prevents oral intake, the benefits of correcting the deficiency (preventing serious maternal and fetal complications) outweigh any minimal risk from the injection. Each ingredient on its own is either Category A (B₆) or essential with no evidence of harm at normal levels (B₁, B₂, B₅) or Category C in very high doses (niacin). Clinicians will typically try standard prenatal vitamins or oral supplementation first, resorting to IM/IV B-complex therapy if those are inadequate or not feasible. When used, monitoring of maternal vital signs and general condition can provide reassurance that no adverse reactions (like excessive hypotension from niacinamide) are occurring. No congenital abnormalities have been linked to these vitamins at the doses provided; indeed, severe deficiencies of B vitamins are a known danger to pregnancy, whereas supplementing them is generally beneficial.

For breastfeeding, the water-soluble vitamins readily pass into breast milk. Lactating women have higher daily needs for B vitamins (for instance, riboflavin 1.6 mg/day, niacin ~17 mg NE/day), because some of the maternal intake is secreted in milk to nourish the infant.^[4] Normal levels of B vitamins in breast milk are desirable, as they support the infant’s developing metabolism. Use of Vitamin B-Complex Injection in a breastfeeding mother will sharply raise her plasma levels of these vitamins, leading to enriched levels in her breast milk. This is not inherently dangerous – the infant will simply receive more B vitamins, and excess will be excreted in the infant’s urine as well. However, high-dose niacin (as a medication for cholesterol) is generally not recommended during breastfeeding, because significant amounts could enter milk and cause unwanted effects in the nursing infant (flushing, for example).^[9]

The doses in this compounded injection are much lower than those therapeutic megadoses, but still higher than typical dietary intake. One study found that lactating women taking 2–60 mg of niacin daily had milk niacin concentrations of 1.17–2.75 μg/mL. With 100 mg nicotinamide administered, levels in milk would likely rise further; while there is no evidence of harm at that level, caution is advised. The recommended daily intake of niacin for lactation is ~17–20 mg, which is easily met by a normal diet.^[9] Therefore, unless the mother has a clear deficiency, routine use of the B-Complex Injection during breastfeeding may be unnecessary. If the injection is needed (e.g., to replete B₁ or B₆ in a deficient mother), it can be used, but the infant should be observed for any unusual symptoms (though none would be expected from B vitamins, apart from perhaps looser stools if anything).

In summary, each vitamin in this injection is either Category A (pyridoxine) or exempt but considered safe at normal intake (thiamine, riboflavin, pantothenic), except niacin which is Category C at high doses but likely safe at modest doses. The injection should be given in pregnancy only if indicated, and under healthcare supervision. It is not a routine prenatal supplementation method but rather a therapeutic intervention for specific needs. When used, it can correct deficiencies that might otherwise jeopardize pregnancy outcomes, thus its judicious use can be very beneficial. Pregnant or breastfeeding patients should discuss with their obstetric provider before starting this injection, and ensure all healthcare team members are aware, so that vitamin levels and any pregnancy-related effects can be monitored appropriately.

Proper storage of the Vitamin B-Complex multi-dose vial is essential to maintain its stability and potency. Refrigeration is required: store the vial at 2°–8°C (36°–46°F). The product should be kept in a refrigerator when not in use, and not left at room temperature for prolonged periods, except for drawing up a dose. Do not freeze the vial. Freezing can cause the vitamins (especially riboflavin and perhaps dexpanthenol) to precipitate or the solution to phase-separate; if the medication accidentally freezes during shipping or storage, it may form crystals or cloudiness.^[6] If that occurs, it can sometimes be salvaged by allowing it to warm to room temperature – if the precipitate re-dissolves completely with gentle warming and shaking, the solution may be usable. However, if any particulate matter remains undissolved or the solution remains cloudy, the vial should be discarded for safety.^[1] Always inspect the solution in good light before withdrawing a dose: it should appear clear and free of particles or haze.

Protect from light: The vial should be stored in its original carton or another light-resistant container until use. Riboflavin (vitamin B₂) is light-sensitive and can degrade with exposure to sunlight or strong UV light, which may reduce the vitamin content and cause the solution to darken. The manufacturer explicitly advises keeping the vial in the carton to shield it from light.^[1] If the solution is drawn into a syringe for injection, it should be administered promptly for the same reason (avoid leaving the filled syringe exposed to light for long).

It is normal for the solution to darken slightly over time under refrigeration, particularly due to the riboflavin content. A slight yellow-orange coloration or darkening does not indicate loss of efficacy – the product information notes that refrigeration can cause a color change (darker yellow) which does not affect safety or effectiveness.^[1] However, any pronounced color change (for example, turning brown) or development of a precipitate should be treated with caution. If in doubt, one should consult the pharmacy or manufacturer for guidance or replace the vial with a fresh supply.

Keep the vial tightly sealed. After each use, ensure the rubber stopper is clean and the cap is on, then return the vial to refrigerated storage. Since this is a multi-dose vial with a preservative, it can be used for multiple doses in the same patient. Nonetheless, it should be used within a certain timeframe as recommended by the pharmacy (often 28 days after first puncture, per general guidelines for multi-dose vials, unless otherwise specified). Marking the date of first use on the label can be helpful. Do not use the vial beyond its labeled expiration date. Expired vitamin solutions may have reduced potency and an increased chance of contamination or chemical breakdown.

The vial should be kept out of reach of children, as with any medication. In a clinical setting, it will be stored in the medication refrigerator. In a home setting, patients should have a designated spot in their refrigerator to store it safely (ideally in a container to avoid contact with food items and with the original box around it). It’s recommended not to freeze (as mentioned) and also to avoid excessive heat – so do not place it near the freezer compartment where freezing could occur, and don’t leave it at room temperature or in a hot car. If the patient needs to transport the medication (e.g., traveling), it should be carried in a cooler bag with ice packs to maintain the cold chain.

By adhering to these storage instructions – keep cold, protect from light, do not freeze, check for clarity – the integrity of the Vitamin B-Complex Injection can be ensured for the duration of its use. Improper storage could lead to vitamin degradation (losing potency) or increased risk of injection site reactions (if contaminants or precipitates form), so patients and providers should take the storage guidelines seriously. When stored correctly, this compounded injection remains stable and effective until the stated expiration.

1. Mylan Institutional LLC. (2021). Vitamin B-Complex 100 Injection [Prescribing information]. Revised 09/2021. (Contains description of formulation, indications, dosing, and storage recommendations). (https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=282ccec8-9bcd-4571-9b91-bbb96ef2620d)
2. U.S. Food & Drug Administration. (2018). Compounded drugs are not FDA-approved. In Human Drug Compounding: Laws and Policies. FDA.gov. (Explains that compounded medications under Section 503A are exempt from FDA pre-market approval requirements, meaning their safety and efficacy are not evaluated by FDA prior to use). (https://www.fda.gov/drugs/human-drug-compounding/human-drug-compounding-laws)
3. Kennedy, D. O. (2016). B Vitamins and the Brain: Mechanisms, Dose and Efficacy – A Review. Nutrients, 8(2), 68. https://doi.org/10.3390/nu8020068 (Comprehensive review detailing the inter-related roles of B-complex vitamins in cellular metabolism, energy production, and neurological function). (https://doi.org/10.3390/nu8020068)
4. Harvard T.H. Chan School of Public Health. (n.d.). Riboflavin – Vitamin B2 (Fact Sheet). The Nutrition Source. Retrieved May 3, 2025, from https://www.hsph.harvard.edu (Notes that riboflavin is a key coenzyme in energy metabolism; excess is excreted in urine, often causing bright yellow coloration, and no upper toxicity level has been observed). (https://nutritionsource.hsph.harvard.edu/riboflavin-vitamin-b2/)
5. Abosamak, N. R., & Gupta, V. (2023). Vitamin B6 (Pyridoxine). In StatPearls [Internet]. StatPearls Publishing. (Updated August 17, 2023). (Provides pharmacological details on pyridoxine, including its role as a coenzyme in neurotransmitter synthesis and interactions such as the antagonism of levodopa and reduction of phenytoin levels). (https://www.statpearls.com/point-of-care/640)
6. McGuff Medical. (2023). Vitamin B Complex 100 Injection (with Dexpanthenol) – Product Information. McGuff.com. (Product listing for a similar compounded B-complex injection; includes warnings that parenteral thiamine may cause anaphylaxis and that the benzyl alcohol preservative is contraindicated in neonates due to risk of serious reactions). (https://www.mcguff.com/vitamin-b-complex-100-injection-with-dexpanthenol-multiple-dose-vial-30-ml)
7. Djadjo, S., & Bajaj, T. (2023). Niacin (Vitamin B3). In StatPearls [Internet]. StatPearls Publishing. (Updated March 20, 2023). (Outlines contraindications for niacin therapy, including active peptic ulcer disease, active liver disease with elevated enzymes, hypersensitivity to niacin, and arterial bleeding, as well as monitoring recommendations for blood pressure, glucose, uric acid, etc., due to niacin’s systemic effects). (https://www.statpearls.com/point-of-care/38460)
8. Mount Sinai Health Library. (n.d.). Vitamin B3 (Niacin). Retrieved May 3, 2025, from https://www.mountsinai.org/health-library/supplement/vitamin-b3-niacin (Cautions that people with low blood pressure or a history of gout should not take niacin/niacinamide due to risk of hypotension and hyperuricemia; also notes need for medical supervision in coronary artery disease). (https://www.mountsinai.org/health-library/nutrition/niacin)
9. Drugs.com. (2023). Niacin – Pregnancy and Breastfeeding Warnings. Retrieved May 1, 2025, from Drugs.com database. (States that niacin should be used in pregnancy only if the benefit outweighs the risk; classified as FDA Pregnancy Category C. Notes that high-dose niacin passes into breast milk and that lipid-altering doses could pose risks to nursing infants, recommending caution or avoidance of such doses during breastfeeding). (https://www.drugs.com/pregnancy/niacin.html)
10. Drugs.com. (2024). Pyridoxine (Vitamin B6) – Pregnancy and Breastfeeding Warnings. Retrieved May 1, 2025. (Documents that pyridoxine is FDA Pregnancy Category A with increased requirements in pregnancy and is commonly used to treat morning sickness. Indicates that no adverse fetal effects have been observed at normal doses and that pyridoxine is considered safe and often beneficial in pregnancy. Also notes it is excreted in breast milk but is safe at nutritional levels). (https://www.drugs.com/pregnancy/pyridoxine.html)
11. National Institutes of Health, Office of Dietary Supplements. (2022). Niacin: Fact Sheet for Health Professionals. Retrieved from https://ods.od.nih.gov (Provides insight into niacin’s safety profile: nicotinic acid commonly causes flushing at doses ≥30 mg; high pharmacologic doses (1–3 g/day) can cause hypotension, insulin resistance, and hepatotoxicity. Nicotinamide (niacinamide) does not cause flushing and has fewer side effects, with nausea and liver toxicity reported only at very high intakes ~3 g/day). (https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/)
12. Cleveland Clinic. (2025). General Medication Guidelines – Missed Dose Instructions. In Patient Education – Vitamins. ClevelandClinic.org. (Advises that if a dose is missed, take it as soon as possible unless it’s almost time for the next dose, in which case skip the missed dose. Emphasizes not to double doses. This general rule applies to maintaining consistent supplementation schedules for vitamins). (https://my.clevelandclinic.org/health/drugs/23803-vitamin-b-complex-tablets-or-capsules)