Hyoscyamine, Phenobarbital & Nutrient Depletion
Also searched as Levsin Pb, Levsinex Pb Timecaps. What the clinical evidence reports, what it may mean, and what to discuss with your pharmacist.
Hyoscyamine, Phenobarbital has been associated with depletion of ACETYL-L-CARNITINE, L-CARNITINE, PROPIONYL-L-CARNITINE and BIOTIN and 6 more. This does not mean a deficiency will occur — it means these are worth knowing about and, if you take Hyoscyamine, Phenobarbital long-term, worth raising with your pharmacist or healthcare provider.
Take more than one medication? Open the checker with Hyoscyamine, Phenobarbital pre-loaded and add the rest to see overlapping nutrient signals.
Reported nutrient depletions with Hyoscyamine, Phenobarbital
Each record below is shown as published in our licensed clinical database, with its evidence rating and citations. Expand a section for food sources and talking points.
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ACETYL-L-CARNITINE
Insignificant DepletionPHENOBARBITAL (Luminal)
Data on the effect of phenobarbital on blood levels of carnitines are conflicting. Some studies have found reduced L-carnitine levels in some patients taking phenobarbital. However, other studies have found no significant effect. Routine L-carnitine or acetyl-L-carnitine supplementation does not seem to be necessary.
Acetyl-L-carnitine is a compound your body uses to help turn fat into energy and support nerve cell function. The phenobarbital component of this combination has shown up in some research as possibly affecting carnitine levels in the blood, though scientists are not fully agreed on this, and other studies found no real change at all. Given that rating of insignificant depletion, most people taking this medication do not need to worry about this or consider a supplement. That said, if you have any concerns, your pharmacist or doctor is always a good place to start.
Learn more about this nutrient: Acetyl-l-carnitine — uses, safety & interactions
References (5)
- Hug G, McGraw CA, Bates SR, et al. Reduction of serum carnitine concentrations during anticonvulsant therapy with phenobarbital, valproic acid, phenytoin, and carbamazepine in children. J Pediatr 1991;119:799-802. PubMed
- Castro-Gago M, Eiris-Punal J, Novo-Rodriguez MI, et al. Serum carnitine levels in epileptic children before and during treatment with valproic acid, carbamazepine, and phenobarbital. J Child Neurol 1998;13:546-9. PubMed
- Thom H, Carter PE, Cole GF, et al. Ammonia and carnitine concentrations in children treated with sodium valproate compared with other anticonvulsant drugs. Dev Med Child Neurol 1991;33:795-802. PubMed
- Zelnik N, Fridkis I, Gruener N. Reduced carnitine and antiepileptic drugs: cause relationship or co-existence? Acta Paediatr 1995;84:93-5. PubMed
- Opala G, Winter S, Vance C, et al. The effect of valproic acid on plasma carnitine levels. Am J Dis Child 1991;145:999-1001. PubMed
L-CARNITINE
Insignificant DepletionPHENOBARBITAL (Luminal)
Some studies have found reduced levels of L-carnitine in some patients taking phenobarbital. However, other studies have found no significant effect. Routine L-carnitine supplementation does not seem to be necessary.
Phenobarbital, one of the ingredients in this combination, has shown up in some research as potentially interfering with how the body handles L-carnitine, a compound your muscles and cells use to turn fat into usable energy. The picture from studies is mixed though: some found lower carnitine levels in people taking phenobarbital, while others found no real difference at all. Given that this is rated as insignificant, most people on this medication do not need to worry about it or take a supplement, but if you have been on it long-term and have any concerns, a quick conversation with your pharmacist or doctor can give you peace of mind.
What Carnitine does & food sources
Carnitine shuttles fatty acids into cells' mitochondria so they can be burned for energy.
Common food sources:
- Red meat (the richest source)
- Poultry and fish
- Dairy products
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
Carnitine questions come up with specific medications (for example, valproic acid) and specific situations — this is a conversation for your prescriber, who can weigh testing or supplementation.
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Supplement considerations
Carnitine supplements are usually reserved for clinician-identified situations rather than general use.
Do not start or stop medications or supplements without professional guidance — supplements can interact with prescription medications.
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Learn more about this nutrient: L-carnitine — uses, safety & interactions
References (5)
- Hug G, McGraw CA, Bates SR, et al. Reduction of serum carnitine concentrations during anticonvulsant therapy with phenobarbital, valproic acid, phenytoin, and carbamazepine in children. J Pediatr 1991;119:799-802. PubMed
- Castro-Gago M, Eiris-Punal J, Novo-Rodriguez MI, et al. Serum carnitine levels in epileptic children before and during treatment with valproic acid, carbamazepine, and phenobarbital. J Child Neurol 1998;13:546-9. PubMed
- Thom H, Carter PE, Cole GF, et al. Ammonia and carnitine concentrations in children treated with sodium valproate compared with other anticonvulsant drugs. Dev Med Child Neurol 1991;33:795-802. PubMed
- Zelnik N, Fridkis I, Gruener N. Reduced carnitine and antiepileptic drugs: cause relationship or co-existence? Acta Paediatr 1995;84:93-5. PubMed
- Opala G, Winter S, Vance C, et al. The effect of valproic acid on plasma carnitine levels. Am J Dis Child 1991;145:999-1001. PubMed
PROPIONYL-L-CARNITINE
Insignificant DepletionPHENOBARBITAL (Luminal)
Data on the effect of phenobarbital on blood levels of carnitines are conflicting. Some studies have found reduced levels in some patients taking phenobarbital. However, other studies have found no significant effect. Routine L-carnitine or propionyl-L-carnitine supplementation does not seem to be necessary.
Propionyl-L-carnitine is a compound your body uses to help turn fats into energy, particularly in muscle tissue. The phenobarbital component of this combination has shown up in some research as potentially lowering carnitine levels, though other studies found no meaningful change at all. Because the evidence is genuinely mixed and the overall rating here is insignificant, most people taking this medication do not need to worry about or act on this. If you take phenobarbital long-term and have concerns, it is worth a quick conversation with your pharmacist or doctor.
Learn more about this nutrient: Propionyl-l-carnitine — uses, safety & interactions
References (5)
- Hug G, McGraw CA, Bates SR, et al. Reduction of serum carnitine concentrations during anticonvulsant therapy with phenobarbital, valproic acid, phenytoin, and carbamazepine in children. J Pediatr 1991;119:799-802. PubMed
- Castro-Gago M, Eiris-Punal J, Novo-Rodriguez MI, et al. Serum carnitine levels in epileptic children before and during treatment with valproic acid, carbamazepine, and phenobarbital. J Child Neurol 1998;13:546-9. PubMed
- Thom H, Carter PE, Cole GF, et al. Ammonia and carnitine concentrations in children treated with sodium valproate compared with other anticonvulsant drugs. Dev Med Child Neurol 1991;33:795-802. PubMed
- Zelnik N, Fridkis I, Gruener N. Reduced carnitine and antiepileptic drugs: cause relationship or co-existence? Acta Paediatr 1995;84:93-5. PubMed
- Opala G, Winter S, Vance C, et al. The effect of valproic acid on plasma carnitine levels. Am J Dis Child 1991;145:999-1001. PubMed
BIOTIN
Moderate DepletionPHENOBARBITAL (Luminal)
Reduced plasma biotin levels can occur in people taking phenobarbital. In one study, plasma levels were 50% lower in people taking phenobarbital or various other anticonvulsants than in controls. There may also be increased urinary excretion of organic acids, an indicator of reduced biotin-dependent enzyme activity. Suggested mechanisms include competitive inhibition of biotin transport in the intestine, increased catabolism of biotin, and decreased renal tubular reabsorption of biotin. Phenobarbital contains a carbamide group, which is also present in biotin, and may lead to competition for intestinal and renal tubular absorption sites. The clinical significance of these effects on biotin isn't clear.
Phenobarbital (one of the two ingredients in this combination) is the part that raises concern here: it appears to interfere with biotin, a B vitamin your body uses to turn food into energy and keep skin, hair, and nerves healthy. The drug may block absorption of biotin in the gut, cause the kidneys to flush out more of it in urine, and speed up how fast the body breaks it down. Blood levels roughly half those of people not on the drug have been reported, so this is rated moderate and worth keeping an eye on. If you have been taking this medication long term, it is a reasonable thing to bring up with your pharmacist or doctor to find out whether monitoring or a supplement makes sense for you.
Learn more about this nutrient: Biotin — uses, safety & interactions
References (7)
- Krause KH, Bonjour JP, Berlit P, Kochen W. Biotin status of epileptics. Ann N Y Acad Sci 1985;447:297-313.
- Krause KH, Kochen W, Berlit P, Bonjour JP. Excretion of organic acids associated with biotin deficiency in chronic anticonvulsant therapy. Int J Vitam Nutr Res 1984;54:217-22.
- Krause KH, Berlit P, Bonjour JP. Vitamin status in patients on chronic anticonvulsant therapy. Int J Vitam Nutr Res 1982;52:375-85.
- Mock DM, Dyken ME. Biotin deficiency results from long-term therapy with anticonvulsants (abstract). Gastroenterology 1995;108:A740. DOI
- Mock DM, Mock NI, Nelson RP, Lombard KA. Disturbances in biotin metabolism in children undergoing long-term anticonvulsant therapy. J Pediatr Gastroentereol Nutr 1998;26:245-50.
- Mock DM, Dyken ME. Biotin catabolism is accelerated in adults receiving long-term therapy with anticonvulsants. Neurology 1997;49:1444-7. PubMed
- Rathman SC, Eisenschenk S, McMahon RJ. The abundance and function of biotin-dependent enzymes are reduced in rats chronically administered carbamazepine. J Nutr 2002;132:3405-10. PubMed
CALCIUM
Moderate DepletionPHENOBARBITAL (Luminal)
Phenobarbital decreases calcium absorption by increasing metabolism of vitamin D, which is needed for calcium absorption. Hypocalcemia and osteomalacia have occurred, especially with prolonged therapy or when used in combination with carbamazepine and/or phenytoin. Advise patients taking phenytoin for six months or more that they may also need vitamin D and calcium supplements. For information on foods that are rich in calcium, see our chart.
Phenobarbital, the anticonvulsant in this combination, can quietly work against calcium, which your bones, muscles, and heart depend on. It does this indirectly: the drug speeds up the liver's breakdown of vitamin D, and without enough vitamin D your gut simply cannot absorb calcium properly. Because this effect builds over time, people who take phenobarbital for six months or longer are the ones most worth watching. If that sounds like you, it is worth asking your doctor or pharmacist whether your calcium and vitamin D levels should be checked.
What Calcium does & food sources
Calcium builds and maintains bone and is essential for muscle contraction and nerve signaling.
Common food sources:
- Dairy products (milk, yogurt, cheese)
- Fortified plant milks and juices
- Canned fish with bones (sardines, salmon)
- Leafy greens like kale
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
Ask your provider whether bone health monitoring (and vitamin D testing) makes sense with long-term use of an associated medication — a blood calcium level alone does not capture bone calcium status.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Supplement considerations
Calcium can interfere with the absorption of several medications (some antibiotics, thyroid medication, iron) — separate the doses and confirm timing with your pharmacist. Total intake from food plus supplements matters more than supplements alone.
Do not start or stop medications or supplements without professional guidance — supplements can interact with prescription medications.
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Caution: Very high calcium intake has its own risks (kidney stones in susceptible people) — more is not better.
Learn more about this nutrient: Calcium — uses, safety & interactions
References (5)
- Gough H, Goggin T, Bissessar A, et al. A comparative study of the relative influence of different anticonvulsant drugs, UV exposure and diet on vitamin D and calcium metabolism in out-patients with epilepsy. Quart J Med 1986;59:569-77. DOI
- Hoikka V, Alhava EM, Karjalainen P, et al. Carbamazepine and bone mineral metabolism. Acta Neurol Scand 1984;70:77-80. PubMed
- Rajantie J, Lamberg-Allardt C, Wilska M. Does carbamazepine treatment lead to a need of extra vitamin D in some mentally retarded children? Acta Paediatr Scand 1984;73:325-8. PubMed
- Bell RD, Pak CY, Zerwekh J, et al. Effect of phenytoin on bone and mineral density in ambulatory epileptic children. Brain Dev 1994;16:382-5.
- Collins N, Maher J, Cole M, et al. A prospective study to evaluate the dose of vitamin D required to correct low 25-hydroxyvitamin D levels, calcium, and alkaline phosphatase in patients at risk of developing antiepileptic drug-induced osteomalacia. Q J M
FOLIC ACID
Moderate DepletionPHENOBARBITAL (Luminal)
In people with low dietary folate intake, phenobarbital might reduce serum folate levels leading to megaloblastic anemia, and possibly contributing to neurological side effects, mental changes, and cerebral atrophy. Possible mechanisms include reduced folic acid absorption, increased metabolism, increased demand for folic acid as a coenzyme for induced hepatic enzymes, or competitive interaction between folate coenzymes and phenobarbital. Pregnant patients taking phenobarbital may be especially at risk for reduced folate levels, as low folate levels during pregnancy may contribute to birth defects and pregnancy loss. Folic acid therapy seems to reverse these neurological effects. However, folic acid can worsen seizure control. Advise patients taking phenobarbital to consult their physician before taking folic acid supplements. For information on foods that are rich in folate, see our chart.
Phenobarbital, one of the ingredients in this combination, is the part that raises concern about folate, a B vitamin your body uses to build healthy red blood cells and support nerve function. Over time, phenobarbital appears to speed up how the liver breaks down folate and may also reduce how well the gut absorbs it, which can leave less of it available in the blood. This is rated a moderate depletion, so it is worth paying attention to, especially if your diet is low in folate-rich foods or if you are pregnant. Before reaching for a supplement, though, please talk with your doctor first, because folic acid can interact with seizure control in some people taking phenobarbital.
What Folic acid (folate) does & food sources
Folate is needed for cell division, red blood cell formation, and healthy fetal development.
Common food sources:
- Leafy green vegetables
- Beans, lentils, and peas
- Fortified grains and cereals
- Citrus fruits
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
Ask your provider whether folate monitoring or supplementation is appropriate for you — this matters most before and during pregnancy, and with long-term use of certain seizure or arthritis medications.
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Supplement considerations
Folate needs are individual. With some medications (for example, methotrexate), folic acid is often prescribed deliberately on a specific schedule — follow your prescriber's instructions rather than adding your own.
Do not start or stop medications or supplements without professional guidance — supplements can interact with prescription medications.
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Caution: High-dose folic acid can mask vitamin B12 deficiency, so the two are often evaluated together.
Learn more about this nutrient: Folic Acid — uses, safety & interactions
References (10)
- Froscher W, Maier V, Laage M, et al. Folate deficiency, anticonvulsant drugs, and psychiatric morbidity. Clin Neuropharmacol 1995;18:165-82. PubMed
- Taliani U, Camellini A, Bernardi P, et al. A clinical case of severe megaloblastic anemia during treatment with primidone. Acta Biomed Ateneo Parmense 1989;60:245-8.
- Lambie DG, Johnson RH. Drugs and folate metabolism. Drugs 1985;30:145-55. PubMed
- Botez MI, Peyronnard J, Berube L, Labrecque R. Relapsing neuropathy, cerebral atrophy and folate deficiency. Appl Neurophysiol 1979;42:171-83.. DOI
- Reynolds EH. Neurological aspects of folate and vitamin B12 metabolism. Clin Haematol 1976;5:661-96. DOI
- Reynolds EH. Folate metabolism and anticonvulsant therapy. Proc R Soc Med 1974;67:68.
- Reynolds EH, Trimble MR. Adverse neuropsychiatric effects of anticonvulsant drugs. Drugs 1985;29:570-81. PubMed
- Hiilesmaa VK, Teramo K, Granstrom ML, Bardy AH. Serum folate concentrations during pregnancy in women with epilepsy: relation to antiepileptic drug concentrations, number of seizures, and fetal outcome. Br Med J 1983;287:577-9. DOI
- Dansky LV, Rosenblatt DS, Andermann E. Mechanisms of teratogenesis: folic acid and antiepileptic therapy. Neurology 1992;42:32-42.
- Lewis DP, Van Dyke DC, Stumbo PJ, Berg MJ. Drug and environmental factors associated with adverse pregnancy outcomes. Part I: antiepileptic drugs, contraceptives, smoking, and folate. Ann Pharmacother 1998;32:802-17. PubMed
VITAMIN B12
Moderate DepletionPHENOBARBITAL (Luminal)
In one case report, a 23-year-old male with epilepsy who was taking phenytoin with phenobarbital for two years presented with megaloblastic anemia due to severe decreases in vitamin B12 and folate levels. Theoretically, phenytoin and/or phenobarbital may have interfered with vitamin B12 absorption. Encourage patients to maintain adequate dietary vitamin B12 intake, and check folate and vitamin B12 status if symptoms of anemia develop. If considering alternatives, neither oxcarbazepine (Trileptal), levetiracetam (Keppra), nor valproate have been associated with reduced vitamin B12 levels. For information on foods that are rich in vitamin B12, see our chart.
Vitamin B12 is something your nerves and red blood cells genuinely depend on, and long-term use of phenobarbital has been linked to lower B12 levels, possibly because it interferes with how well the gut absorbs this vitamin. This combination carries a moderate depletion rating, which means it is worth paying attention to, especially over years of use. If you have been on this medication for a long time, it is reasonable to ask your doctor or pharmacist whether checking your B12 and folate levels makes sense for you.
What Vitamin B12 does & food sources
Vitamin B12 supports red blood cell formation, nerve function, and DNA synthesis.
Common food sources:
- Meat, poultry, and fish
- Eggs and dairy products
- Fortified cereals and nutritional yeast
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What to discuss with your clinician
If you take an associated medication long-term, ask your healthcare provider whether checking a vitamin B12 level (sometimes with methylmalonic acid) is appropriate — especially if you notice fatigue, numbness, tingling, or memory changes.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Supplement considerations
B12 status is easy to check and low levels are usually straightforward to address, so testing before supplementing is often the sensible order. High-dose folic acid can mask a B12 deficiency, which is one reason B12 and folate questions are best sorted out together with your provider.
Do not start or stop medications or supplements without professional guidance — supplements can interact with prescription medications.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Caution: B12 deficiency can look like other conditions — do not self-diagnose from symptoms alone.
Learn more about this nutrient: Vitamin B12 — uses, safety & interactions
References (5)
- Reynolds EH, Hallpike JF, Phillips BM, et al. Reversible absorptive defects in anticonvulsant megaloblastic anemia. J Clin Pathol 1965;18:593-8.
- Rezaei S, Shab-Bidar S, Abdurahman AA, Djafarian K. Oxcarbazepine administration and the serum levels of homocysteine, vitamin B12 and folate in epileptic patients: A systematic review and meta-analysis. Seizure. 2017;45:87-94. PubMed
- Sharma TK, Vardey SK, Sitaraman S. Evaluate the Effect of Valproate Monotherapy on the Serum Homocysteine, Folate and Vitamin B12 Levels in Epileptic Children. Clin Lab. 2015;61(8):933-40. PubMed
- Mahdavi A, Naeini AA, Najafi M, Ghazvini M, Maracy M. Vitamin B12 and Folate Status in Patients with Epilepsy Under Levetiracetam Monotherapy. Int J Prev Med. 2019;10:32. PubMed
- Ozdemir O, Yakut A, Dinleyici EC, Aydogdu SD, Yarar C, Colak O. Serum asymmetric dimethylarginine (ADMA), homocysteine, vitamin B(12), folate levels, and lipid profiles in epileptic children treated with valproic acid. Eur J Pediatr. 2011;170(7):873-7.
VITAMIN D
Moderate DepletionPHENOBARBITAL (Luminal)
Phenobarbital increases hepatic metabolism of vitamin D to inactive compounds, thereby reducing calcium absorption. Hypocalcemia and osteomalacia have occurred, especially with prolonged therapy, concurrent use of other enzyme-inducing anticonvulsants, or when other risk factors for vitamin D deficiency are present. Patients taking phenobarbital for 6 months or more may need vitamin D and calcium supplements. Doses of vitamin D needed vary from 400-4000 IU daily. For information on foods that are rich in vitamin D, see our chart.
Phenobarbital, the anticonvulsant component in this combination, can prompt your liver to break down vitamin D much faster than normal, leaving less of it available for your body to use. Vitamin D is what helps your gut absorb calcium and keep your bones strong, so when levels drop over time, bones can gradually weaken. This is a moderate, well-documented concern rather than a rare theoretical one, especially for people who have been on phenobarbital for six months or more. If that describes you, it is worth asking your doctor or pharmacist whether your vitamin D level has been checked and whether a supplement makes sense for you.
What Vitamin D does & food sources
Vitamin D helps the body absorb calcium and supports bone, muscle, and immune health.
Common food sources:
- Fatty fish (salmon, mackerel)
- Fortified milk and cereals
- Egg yolks
- Sunlight exposure (the main natural source)
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
A 25-hydroxyvitamin D blood test is the standard way to assess status — ask whether it is appropriate if you take an associated medication long-term, have limited sun exposure, or have bone concerns.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Supplement considerations
Vitamin D dosing varies a lot between people; some medications change how vitamin D is processed. Your provider can target a dose to your level instead of guessing.
Do not start or stop medications or supplements without professional guidance — supplements can interact with prescription medications.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Caution: Vitamin D is fat-soluble and can accumulate — very high doses over time can cause harm, so follow a clinician-guided plan.
Learn more about this nutrient: Vitamin D — uses, safety & interactions
References (5)
- Gough H, Goggin T, Bissessar A, et al. A comparative study of the relative influence of different anticonvulsant drugs, UV exposure and diet on vitamin D and calcium metabolism in out-patients with epilepsy. Quart J Med 1986;59:569-77. DOI
- Hoikka V, Alhava EM, Karjalainen P, et al. Carbamazepine and bone mineral metabolism. Acta Neurol Scand 1984;70:77-80. PubMed
- Rajantie J, Lamberg-Allardt C, Wilska M. Does carbamazepine treatment lead to a need of extra vitamin D in some mentally retarded children? Acta Paediatr Scand 1984;73:325-8. PubMed
- Bell RD, Pak CY, Zerwekh J, et al. Effect of phenytoin on bone and mineral density in ambulatory epileptic children. Brain Dev 1994;16:382-5.
- Collins N, Maher J, Cole M, et al. A prospective study to evaluate the dose of vitamin D required to correct low 25-hydroxyvitamin D levels, calcium, and alkaline phosphatase in patients at risk of developing antiepileptic drug-induced osteomalacia. Q J M
VITAMIN E
Moderate DepletionPHENOBARBITAL (Luminal)
There is some evidence that children taking phenobarbital have serum vitamin E levels 9% to 26% lower than children with untreated epilepsy. The clinical significance of this effect isn't clear. Vitamin E supplements don't seem to be harmful in children with epilepsy. They've been associated with either no effect on seizure control, or improved seizure control. Advise patients to maintain the recommended dietary intake of vitamin E. Consider supplements if plasma vitamin E levels are low (below 5 micrograms/mL).
Vitamin E is an antioxidant your body uses to protect cells and support immune function, and research in children taking phenobarbital has found their vitamin E levels running noticeably lower than expected. The leading theory is that phenobarbital speeds up liver enzymes that break down vitamin E faster than normal, leaving less of it circulating in the blood. Because this is rated moderate depletion, it is worth paying attention to, especially for longer-term users. Eating vitamin E-rich foods like nuts, seeds, and leafy greens is a reasonable first step, and if you are concerned about your levels, ask your pharmacist or doctor whether blood testing or a supplement makes sense for you.
What Vitamin E does & food sources
Vitamin E is a fat-soluble antioxidant that protects cell membranes.
Common food sources:
- Vegetable oils
- Nuts and seeds
- Wheat germ
- Leafy greens
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
Deficiency is rare; ask your provider before supplementing, particularly if you take blood thinners.
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Supplement considerations
Higher-dose vitamin E can increase bleeding tendency, especially with warfarin or antiplatelet medications.
Do not start or stop medications or supplements without professional guidance — supplements can interact with prescription medications.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Caution: Discuss vitamin E supplements with your provider if you take any blood thinner.
Learn more about this nutrient: Vitamin E — uses, safety & interactions
References (6)
- Ogunmekan AO. Relationship between age and vitamin E level in epileptic children and normal children. Am J Clin Nutr 1979;32:2269-71.
- Kataoka K, Kanamori N, Oishi M, et al. Vitamin E status in pediatric patients receiving antiepileptic drugs. Devel Pharmacol Ther 1989;14:96-101. DOI
- Ogunmekan AO. Plasma vitamin E (alpha-tocopherol) levels in normal children and in epileptic children with and without anticonvulsant drug therapy. Trop Geog Med 1985;37:175-7.
- Higashi A, Ikeda T, Matsukura M, Matsuda I. Serum zinc and vitamin E concentrations in handicapped children treated with anticonvulsants. Devel Pharmacol Ther 1982;5:109-13. DOI
- Higashi A, Tamari H, Ikeda T, et al. Serum vitamin E concentration in patients with severe multiple handicaps treated with anticonvulsants. Pediatr Pharmacol 1980;1:129-34.
- Ogunmekan AO, Hwang PA. A randomized, double-blind, placebo-controlled, clinical trial of D-alpha-tocopheryl acetate (vitamin E), as add-on therapy, for epilepsy in children. Epilepsia 1989;30:84-9.
RIBOFLAVIN
Insufficient EvidencePHENOBARBITAL (Luminal)
Some evidence in animals suggests that phenobarbital induces metabolism of riboflavin in the liver. Levels of the active form of riboflavin, flavin adenine dinucleotide (FAD), are increased in the liver and levels of a hydroxylated metabolite are increased in the urine. Also, some animal research suggests that phenobarbital does not significantly affect the content of flavin in the liver.
Riboflavin (vitamin B2) is something your body uses to convert food into energy and keep cells working properly. There is animal research suggesting phenobarbital may cause the liver to process riboflavin faster than usual, potentially affecting active riboflavin levels, but studies in animals have actually shown mixed results. The honest answer right now is that nobody knows how much this matters in people taking the medication long-term. If you have concerns, it is worth bringing up with your pharmacist or doctor at your next visit.
What Vitamin B2 (riboflavin) does & food sources
Riboflavin helps the body produce energy and process other B vitamins.
Common food sources:
- Dairy products and eggs
- Lean meats
- Fortified grains
- Green vegetables
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
What to discuss with your clinician
Deficiency is uncommon with a varied diet; ask your provider if you have persistent mouth-corner cracking, sore tongue, or unexplained fatigue on a long-term associated medication.
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Supplement considerations
Riboflavin is water-soluble and excess is excreted (it turns urine bright yellow — harmless).
Do not start or stop medications or supplements without professional guidance — supplements can interact with prescription medications.
HelloPharmacist pharmacist-reviewed education — separate from the licensed record above.
Learn more about this nutrient: Riboflavin — uses, safety & interactions
References (3)
- Ohkawa H, Ohishi N, Yagi K. Hydroxylation of the 7- and 8-methyl groups of riboflavin by the microsomal electron transfer system of rat liver. J Biol Chem 1983;258:5629-33.. DOI
- Hamajima S, Ono S, Hirano H, Obara K. Induction of the FAD synthetase system in rat liver by phenobarbital administration. Int J Vit Nutr Res 1979;49:59-63..
- Shargel L, Mazel P. Effect of riboflavin deficiency on phenobarbital and 3-methylcholanthrene induction of microsomal drug-metabolizing enzymes of the rat. Biochem Pharmacol. 1973;22(19):2365-73. PubMed
This tool is educational and is not a substitute for professional medical advice. An association is not a diagnosis and does not mean a deficiency will occur. Always talk to your pharmacist or healthcare provider before starting, stopping, or changing any medication or supplement.
Disclaimer: This checker finds which nutrients might be depleted by prescription or over-the-counter medications. Each nutrient depletion issue is rated based on clinical significance. Use your own professional judgment prior to making clinical decisions.© 2026 Therapeutic Research Center Licensed records refresh weekly · last updated July 3, 2026.
More about Hyoscyamine, Phenobarbital
What drug-induced nutrient depletion means
Some medications can, over time, lower the levels of certain vitamins, minerals, or other nutrients — through reduced absorption, increased loss, or changes in how the body uses them.
Association is not deficiency
An entry here means a depletion has been reported or studied — not that it happens to everyone, or that you are deficient. Dose, duration, diet, and your own health all matter.
Evidence varies by pair
Some drug–nutrient links (like metformin and vitamin B12) are well studied; others rest on limited or preliminary research. Each entry shows the evidence rating from our licensed clinical database.
When to ask about labs
If you take an associated medication long-term, ask your healthcare provider whether monitoring is appropriate for you. Not everyone needs testing — your provider can weigh your dose, duration, and symptoms.
Don't self-supplement blindly
Supplements are not risk-free: some can interact with medications, and some (like potassium or magnesium) can be risky with kidney disease. Talk to your pharmacist before adding anything.
Never stop a medication over this
These medications are prescribed for good reasons, and the benefit usually far outweighs a manageable nutrient consideration. Any change belongs in a conversation with your prescriber.
Food first, usually
For many nutrients, a varied diet covers the gap. Each entry lists common food sources; a supplement is a decision to make with your pharmacist or provider, not a default.
Hyoscyamine, Phenobarbital & nutrients: FAQs
Does Hyoscyamine, Phenobarbital deplete ACETYL-L-CARNITINE?
Should I take a supplement because I take Hyoscyamine, Phenobarbital?
Should I stop taking Hyoscyamine, Phenobarbital?
Where does this information come from?
Questions about Hyoscyamine, Phenobarbital and your nutrition?
Ask a licensed pharmacist — free, no appointment needed.
Sources & How We Checked
Nutrient depletion records for Hyoscyamine, Phenobarbital are evidence-graded and sourced from the Natural Medicines database, and are displayed as published with their citations.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for drug-induced nutrient depletions, supplements, and interactions — the basis for this page.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for medication overviews across the site.
Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.