B-carotene

Beta-carotene/Drug Interactions:

  • AlcoholAlcohol: In human research, beta-carotene increased the risk of intracerebral hemorrhage in patients who also drank alcohol (145). In human research, increased alcohol consumption was associated with decreased beta-carotene changes with supplementation (92). According to secondary sources, beta-carotene supplementation may increase liver toxicity and promote cancer when used in combination with heavy alcohol consumption.
  • Alzheimer's agentsAlzheimer's agents: In epidemiological research, there were inconsistent relationships between dietary intake of beta-carotene and Alzheimer's disease risk (155; 156). In human research, long-term use of beta-carotene improved cognition (157).
  • AntiasthmaticsAntiasthmatics: Various reviews have been written on the interest in antioxidants, including beta-carotene, for asthma (158; 159; 160; 161). In human research, a mixture of oral beta-carotene isomers prevented exercise-induced asthma (162).
  • AntibioticsAntibiotics: In patients with pulmonary infection in cystic fibrosis, beta-carotene lacked adjuvant effects (163). In human research, oral neomycin sulfate 4-12g daily reduced levels of beta-carotene (85).
  • AnticoagulantsAnticoagulants: In human research, beta-carotene increased the risk of intracerebral hemorrhage in patients who also drank alcohol (145). According to secondary sources, unusual bleeding or bruising may occur.
  • Antidiabetic agentsAntidiabetic agents: Although epidemiological research suggests that high serum levels of beta-carotene are associated with a reduced risk of developing type 2 diabetes and that impaired insulin sensitivity is associated with low serum beta-carotene (164), information from two randomized controlled trials included in a systematic review suggested that there is a lack of effect of beta-carotene on diabetes (119).
  • Antigout agentsAntigout agents: In human research, short-term treatment with colchicine 1.9-3.9mg daily (165), but not long-term use of 1-2mg daily (166), reduced plasma beta-carotene levels.
  • Anti-inflammatory agentsAnti-inflammatory agents: In human research, short-term treatment with colchicine 1.9-3.9mg daily (165), but not long-term use of 1-2mg daily (166), reduced plasma beta-carotene levels. In a review, the chemopreventive effects of natural dietary compounds in general were suggested as including antioxidative effects, anti-inflammatory activity, induction of phase II enzymes, apoptosis, and cell cycle arrest (details related to beta-carotene are lacking) (167).
  • Antilipemic agentsAntilipemic agents: In human research, a combination of beta-carotene, selenium, and vitamins C and E decreased HDL2 in patients treated with simvastatin and niacin (109; 110). In human research, a combination of beta-carotene and vitamin A increased total cholesterol levels (111). In human research, beta-carotene reduced the effect of simvastatin on stenosis regression, resulting in progression (109). In human research, simvastatin, cholestyramine (Questran?), and colestipol (Colestid?) decreased blood levels of beta-carotene (86; 87; 88)
  • Antineoplastic agentsAntineoplastic agents: Although observational research suggests that greater dietary intake of beta-carotene lowers the incidence of adverse effects in children undergoing chemotherapy for lymphoblastic leukemia (168), in theory, high-dose antioxidants may interfere with the activity of some chemotherapy drugs or radiation therapy. In human research, beta-carotene lacked an effect on chemotherapy-induced mucositis (117), and antioxidant supplementation containing beta-carotene lacked an effect on chemotherapy efficacy (169). Also, supplemental beta-carotene has been shown to increase the risk of lung, prostate, gastric, and urothelial cancers; intracerebral hemorrhage; and cardiovascular and total mortality, especially in people who smoke cigarettes, drink alcohol, have liver disease, or have a history of high-level exposure to asbestos (18; 22; 23; 24; 25; 26; 27; 30; 31; 19; 20; 21; 124; 125; 126; 127; 128; 129; 145; 29; 105; 106; 28).
  • Antiulcer and gastric acid-reducing agentsAntiulcer and gastric acid-reducing agents: In human research, omeprazole decreased the absorption of a single dose of beta-carotene (102).
  • Antiviral agentsAntiviral agents: In human research, beta-carotene lacked effect on HIV viral load, but CD4 counts increased (79). According to LactMed, in HIV-infected women, supplemental high-dose beta-carotene plus vitamin A increased HIV viral shedding into breast milk, as well as HIV infection of the infant, without affecting mortality in the first two years of life, possibly due to increased subclinical mastitis.
  • Cardiovascular agentsCardiovascular agents: In human research, beta-carotene increased the risk of fatal coronary heart disease (29; 27) and reduced the effect of simvastatin on stenosis regression, resulting in progression (109), and a combination of beta-carotene and vitamins C and E prevented beneficial vascular remodeling in patients after angioplasty by promoting fibrosis at the site of angioplastic intervention (104). In human research, a slight (not statistically significant) increase in the incidence of angina was reported (112).
  • Dermatologic agentsDermatologic agents: In human research, beta-carotene supplementation caused hypercarotenodermia (yellowing or discoloration of skin) (75; 76; 77; 78; 79; 31). In human research, beta-carotene, alone or in combination with other antioxidants, prevented UV-induced erythema (170; 171). In human research, beta-carotene had mixed effects on photoprotection in individuals with erythropoietic protoporphyria (120) and appeared to lack effect in patients with polymorphous light eruption when used alone (172; 173; 174; 175; 176; 177; 178; 179).
  • Gastrointestinal agentsGastrointestinal agents: In human research, beta-carotene caused belching (75; 77; 80; 78; 31), as well as gastrointestinal symptoms, including constipation and diarrhea (81; 77; 80). In human research, omeprazole decreased the absorption of a single dose of beta-carotene (102).
  • Hepatic agentsHepatic agents: In human research, combination antioxidant supplements containing beta-carotene increased mortality in patients with liver disease and decreased various liver enzymes (the statistical significance of these endpoints is unclear) (105; 106).
  • ImmunostimulantsImmunostimulants: In human research, beta-carotene increased CD4 counts; these effects were lacking when beta-carotene was administered with a multivitamin (79). In human research, beta-carotene lacked effects on cell-mediated immunity (180).
  • ImmunosuppressantsImmunosuppressants: In human research, beta-carotene increased CD4 counts; these effects were lacking when beta-carotene was administered with a multivitamin (79). In human research, beta-carotene lacked effects on cell-mediated immunity (180).
  • IronIron: In human research, beta-carotene improved anemia (121). In infants, iron supplementation increased vitamin A deficiency (91).
  • Mineral oilMineral oil: In human research, mineral oil reduced serum beta-carotene levels (94).
  • Musculoskeletal agentsMusculoskeletal agents: In human research, muscle pain was reported with beta-carotene supplementation (72). According to secondary sources, joint pain is also a potential adverse effect of beta-carotene. In human research, perioperative supplementation with micronutrients with antioxidant properties (beta-carotene, vitamins C and E, zinc, and selenium) had limited effects on strength and physical function following major elective surgery (181).
  • Neurologic agentsNeurologic agents: In human research, headache was reported with beta-carotene supplementation (72). According to secondary sources, dizziness is also a potential adverse effect of beta-carotene.
  • NicotineNicotine: In human research, beta-carotene increased the incidence of lung and prostate cancer, as well as cancer in general, in smokers (22; 23; 24; 26; 27; 28). The authors of a systematic review noted that beta-carotene may have pro-oxidant properties when used in combination with smoking (27). According to secondary sources, cigarette smoking decreases serum levels of beta-carotene.
  • Ophthalmic agentsOphthalmic agents: In human research, treatment with beta-carotene and canthaxanthin resulted in glistening bright yellow crystalline deposits around the maculae, resulting in a slight decrease in visual acuity and adaptation to the dark (82). Although taking beta-carotene and other antioxidants has been proposed to help prevent or delay progression of age-related macular degeneration (AMD) and is the topic of various reviews (182; 183; 184; 185), effects of beta-carotene on AMD prevention and progression are lacking in the limited available research (81; 115). Also, in human research, effects of beta-carotene on cataract prevention are lacking (76).
  • Orlistat (Xenical)Orlistat (Xenical?): According to the company website, orlistat can decrease absorption of beta-carotene and it is recommended that patients take a multivitamin supplement at least two hours apart from orlistat.
  • Respiratory agentsRespiratory agents: In subjects carrying out heavy exercise at leisure, a combination of vitamin E and beta-carotene increased the risk of colds (83); pulmonary exacerbations have been reported as adverse effects of beta-carotene (84). In human research, increased dietary or plasma levels of beta-carotene was associated with improved FEV1 and FVC; however, beta-carotene alone or as part of combination therapy resulted in an overall lack of effect on chronic obstructive pulmonary disease (COPD) itself or symptoms of COPD (118), as well as on lung function in patients with cystic fibrosis (84). In human research, a mixture of oral beta-carotene isomers prevented exercise-induced asthma (162).
  • Thyroid hormonesThyroid hormones: According to secondary sources, thyroid hormones affect the conversion of beta-carotene to vitamin A in the body.

    • Beta-carotene/Herb/Supplement Interactions:

  • AlcoholAlcohol: In human research, beta-carotene increased the risk of intracerebral hemorrhage in patients who also drank alcohol (145). In human research, increased alcohol consumption was associated with decreased beta-carotene changes with supplementation (92). According to secondary sources, beta-carotene supplementation may increase liver toxicity and promote cancer when used in combination with heavy alcohol consumption.
  • Alzheimer's agentsAlzheimer's agents: In epidemiological research, there were inconsistent relationships between dietary intake of beta-carotene and Alzheimer's disease risk (155; 156). In human research, long-term use of beta-carotene improved cognition (157).
  • AntiasthmaticsAntiasthmatics: Various reviews have been written on the interest in antioxidants, including beta-carotene, for asthma (158; 159; 160; 161). In human research, a mixture of oral beta-carotene isomers prevented exercise-induced asthma (162).
  • AntibioticsAntibiotics: In patients with pulmonary infection in cystic fibrosis beta-carotene lacked adjuvant effects (163). In human research, an antibacterial agent reduced levels of beta-carotene (85).
  • AnticoagulantsAnticoagulants: In human research, beta-carotene increased the risk of intracerebral hemorrhage in patients who also drank alcohol (145). According to secondary sources, unusual bleeding or bruising may occur.
  • Antigout agentsAntigout agents: In human research, short-term treatment with colchicine 1.9-3.9mg daily (165), but not long-term use with 1-2mg daily (166), reduced plasma beta-carotene levels.
  • Anti-inflammatory agentsAnti-inflammatory agents: In human research, short-term treatment with colchicine 1.9-3.9mg daily (165), but not long-term use with 1-2mg daily (166), reduced plasma beta-carotene levels. In a review, the chemopreventive effects of natural dietary compounds in general were suggested as including antioxidative effects, anti-inflammatory activity, induction of phase II enzymes, apoptosis, and cell cycle arrest (details related to beta-carotene are lacking) (167).
  • Antilipemic agentsAntilipemic agents: In human research, a combination of beta-carotene, selenium, and vitamins C and E decreased HDL2 in patients treated with simvastatin and niacin (109; 110). In human research, a combination of beta-carotene and vitamin A increased total cholesterol levels (111). In human research, beta-carotene reduced the effect of an antilipemic agent on stenosis regression, resulting in progression (109). In human research, antilipemic agents decreased blood levels of beta-carotene (86; 87; 88).
  • Antineoplastic agentsAntineoplastic agents: Although observational research suggests that greater dietary intake of beta-carotene lowers the incidence of adverse effects in children undergoing chemotherapy for lymphoblastic leukemia (168), in theory, high-dose antioxidants may interfere with the activity of some chemotherapy drugs or radiation therapy. In human research, beta-carotene lacked an effect on chemotherapy-induced mucositis (117), and antioxidant supplementation containing beta-carotene, lacked an effect on chemotherapy efficacy (169). Also, supplemental beta-carotene has been shown to increase the risk of lung, prostate, gastric, and urothelial cancers; intracerebral hemorrhage; and cardiovascular and total mortality, especially in people who smoke cigarettes, drink alcohol, have liver disease, or have a history of high-level exposure to asbestos (18; 22; 23; 24; 25; 26; 27; 30; 31; 19; 20; 21; 124; 125; 126; 127; 128; 129; 145; 29; 105; 106; 28).
  • AntioxidantsAntioxidants: In human and in vitro research, beta-carotene, alone or in combination with other antioxidants, had mixed effects on antioxidant endpoints (186; 187; 188; 189; 190; 191; 192; 193). According to the authors of a systematic review, beta-carotene may provide synergistic and more favorable effects when given with other antioxidants (119).
  • Antiulcer and gastric acid-reducing agentsAntiulcer and gastric acid-reducing agents: In human research, omeprazole decreased the absorption of a single dose of beta-carotene (102).
  • Antiviral agentsAntiviral agents: In human research, beta-carotene lacked effect on HIV viral load, but CD4 counts increased (79). According to LactMed, in HIV-infected women, supplemental high-dose beta-carotene plus vitamin A increased HIV viral shedding into breast milk, as well as HIV infection of the infant, without affecting mortality in the first two years of life, possibly due to increased subclinical mastitis.
  • CanthaxanthinCanthaxanthin: In human research, although beta-carotene lacked benefit for polymorphous light eruption (PLE) (172; 173; 174; 175; 176; 177; 178; 179), some benefit was observed using beta-carotene in combination with canthaxanthin (194; 195).
  • Cardiovascular agentsCardiovascular agents: In human research, beta-carotene increased the risk of fatal coronary heart disease (29; 27) and reduced the effect of simvastatin on stenosis regression, resulting in progression (109), and a combination of beta-carotene and vitamins C and E prevented beneficial vascular remodeling in patients after angioplasty by promoting fibrosis at the site of angioplastic intervention (104). In human research, a slight (not statistically significant) increase in the incidence of angina has been reported (112).
  • Dermatologic agentsDermatologic agents: In human research, beta-carotene supplementation caused hypercarotenodermia (yellowing or discoloration of skin) (75; 76; 77; 78; 79; 31). In human research, beta-carotene, alone or in combination with other antioxidants, prevented UV-induced erythema (170; 171). In human research, beta-carotene had mixed effects on photoprotection in individuals with erythropoietic protoporphyria (120) and appeared to lack effect in patients with polymorphous light eruption when used alone (172; 173; 174; 175; 176; 177; 178; 179).
  • Fish oilFish oil: In human research, consumption of a natural carotenoid mixture lowered the increase in oxidative stress and enhanced the plasma triglyceride-lowering effect of fish oil (196).
  • Gastrointestinal agentsGastrointestinal agents: In human research, beta-carotene caused belching (75; 77; 80; 78; 31), as well as gastrointestinal symptoms, including constipation and diarrhea (81; 77; 80). In human research, omeprazole decreased the absorption of a single dose of beta-carotene (102).
  • Hepatic agentsHepatic agents: In human research, combination antioxidant supplements containing beta-carotene increased mortality in patients with liver disease and decreased various liver enzymes (the statistical significance of these endpoints is unclear) (105; 106).
  • Hyperglycemics and hypoglycemicsHyperglycemics and hypoglycemics: Although epidemiological research suggests that high serum levels of beta-carotene is associated with a reduced risk of developing type 2 diabetes and that impaired insulin sensitivity is associated with low serum beta-carotene (164), information from two randomized controlled trials included in a systematic review suggests that there is a lack of effect on beta-carotene on diabetes (119).
  • ImmunomodulatorsImmunomodulators: In human research, beta-carotene increased CD4 counts; these effects were lacking when beta-carotene was administered with a multivitamin (79). In human research, beta-carotene lacked effects on cell-mediated immunity (180).
  • IronIron: In human research, beta-carotene improved anemia (121). In infants, iron supplementation increased vitamin A deficiency (91).
  • LuteinLutein: In human research, beta-carotene supplementation lowered serum lutein concentrations (92). Also, in human research, lutein from a food source did not result in a decrease in beta-carotene concentrations that accompanied use of a lutein supplement (93).
  • LycopeneLycopene: In human research, dietary lycopene lacked effect on blood levels of carotenoids (197).
  • Mineral oilMineral oil: In human research, mineral oil reduced serum beta-carotene levels (94).
  • MultivitaminsMultivitamins: In human research, treatment with high doses of beta-carotene (180mg daily) was associated with increased CD4 counts when given as a monotherapy, but it lacked a significant effect on CD4 levels when administered with a multivitamin (79).
  • Musculoskeletal agentsMusculoskeletal agents: In human research, muscle pain was reported with beta-carotene supplementation (72). According to secondary sources, joint pain is also a potential adverse effect of beta-carotene. In human research, perioperative supplementation with micronutrients with antioxidant properties (beta-carotene, vitamins C and E, zinc, and selenium) had limited effects on strength and physical function following major elective surgery (181).
  • Neurologic agentsNeurologic agents: In human research, headache was reported with beta-carotene supplementation (72). According to secondary sources, dizziness is also a potential adverse effect of beta-carotene.
  • NicotineNicotine: In human research, beta-carotene increased the incidence of lung and prostate cancer as well as cancer in general in smokers (22; 23; 24; 26; 27; 28). The authors of a systematic review noted that beta-carotene may have pro-oxidant properties when used in combination with smoking (27). According to secondary sources, cigarette smoking decreases serum levels of beta-carotene.
  • Ocular agentsOcular agents: In human research, treatment with beta-carotene and canthaxanthin resulted in glistening bright yellow crystalline deposits around the maculae, resulting in a slight decrease in visual acuity and adaptation to the dark (82). Although taking beta-carotene and other antioxidants has been proposed to help prevent or delay progression of age-related macular degeneration (AMD) and is the topic of various reviews (182; 183; 184; 185), effects of beta-carotene on AMD prevention and progression are lacking from limited available research (81; 115). Also, in human research, effects of beta-carotene on cataract prevention are lacking (76).
  • Plant sterolsPlant sterols: In human research, plant sterols reduced beta-carotene levels in some, but not all, studies (95; 96; 97; 98; 99; 100; 101). In human research, consumption of an additional daily serving of a high-carotenoid vegetable or fruit when consuming spreads containing sterol or stanol esters maintained plasma carotenoid concentrations (198).
  • Respiratory agentsRespiratory agents: In subjects carrying out heavy exercise at leisure, a combination of vitamin E and beta-carotene increased the risk of colds (83); pulmonary exacerbations have been reported as adverse effects of beta-carotene (84). In human research, increased dietary or plasma levels of beta-carotene was associated with improved FEV1 and FVC; however, beta-carotene alone or as part of combination therapy resulted in an overall lack of effect on COPD itself or symptoms of COPD (118) as well as on lung function in patients with cystic fibrosis (84). In human research, a mixture of oral beta-carotene isomers prevented exercise-induced asthma (162).
  • Red palm oilRed palm oil: The effect of red palm oil on vitamin A status has been examined, but conclusions were lacking in one study (199). In other human research, red palm oil increased breast milk and plasma levels of beta-carotene (200).
  • Sunflower oilSunflower oil: In human research, sunflower oil increased breast milk and plasma levels of beta-carotene (200).
  • Thyroid agentsThyroid agents: According to secondary sources, thyroid hormones affect the conversion of beta-carotene to vitamin A in the body.
  • Vitamin AVitamin A: In human research, mortality significantly increased in patients using a combination of beta-carotene and vitamin A (78; 24).
  • Vitamin CVitamin C: According to secondary sources, vitamin C affects the conversion of beta-carotene to vitamin A in the body.
  • Vitamin EVitamin E: In human research, a combination of beta-carotene and vitamin E reduced the vitamin E concentration found in the normal colonic mucosa (103). In human research, mortality significantly increased in patients using a combination of beta-carotene and vitamin E (78).
  • ZincZinc: In pregnant women with night blindness and low serum zinc concentrations, zinc increased the effect of vitamin A in the restoration of night vision (201). According to secondary sources, zinc affects the conversion of beta-carotene to vitamin A in the body.

    • Beta-carotene/Food Interactions:

  • AlcoholAlcohol: In human research, beta-carotene increased the risk of intracerebral hemorrhage in patients who also drank alcohol (145). In human research, increased alcohol consumption was associated with decreased beta-carotene changes with supplementation (92). According to secondary sources, beta-carotene supplementation may increase liver toxicity and promote cancer when used in combination with heavy alcohol consumption.
  • Beta-carotene-rich foodBeta-carotene-rich food: In human research, pureed papaya and grated carrots improved vitamin A status (202). In children, serum beta-carotene increased following consumption of a diet moderately high in dark green leafy vegetables (203).
  • Dark green leafy vegetablesDark green leafy vegetables: According to secondary sources, a substantial increase in serum beta-carotene has been seen in children after feeding with a moderately high cumulative dose of dark green leafy vegetables for six weeks.
  • Dietary fatDietary fat: Dietary beta-carotene requires some dietary fat for absorption, and supplemental beta-carotene is similarly absorbed when taken with high-fat (36g of fat) or low-fat (3g of fat) meals (113).
  • Dietary proteinDietary protein: According to secondary sources, protein status affects the conversion of beta-carotene to vitamin A in the body.
  • Fat substitutesFat substitutes: In human research, olestra lowered serum beta-carotene concentrations in healthy people by 27% (89). In human research, sucrose polyesters decreased concentrations of serum carotenoids (90).
  • Iron-rich foodsIron-rich foods: In human research, beta-carotene improved anemia (121). In infants, iron supplementation increased vitamin A deficiency (91).
  • Lutein-containing foodsLutein-containing foods: In human research, beta-carotene supplementation lowered serum lutein concentrations (92). Also, in human research, lutein from a food source did not result in a decrease in beta-carotene concentrations that accompanied use of a lutein supplement (93).
  • LycopeneLycopene: In human research, dietary lycopene lacked an effect on blood levels of carotenoids (197).
  • Plant sterolsPlant sterols: In human research, plant sterols reduced beta-carotene levels in some, but not all, studies (95; 96; 97; 98; 99; 100; 101). In human research, consumption of an additional daily serving of a high-carotenoid vegetable or fruit when consuming spreads containing sterol or stanol esters maintained plasma carotenoid concentrations (198).
  • Red palm oilRed palm oil: The effect of red palm oil on vitamin A status has been examined, but conclusions were lacking in one study (199). In other human research, red palm oil increased breast milk and plasma levels of beta-carotene (200).
  • Salad dressingSalad dressing: According to secondary sources, essentially no absorption of carotenoids was observed when salads with fat-free salad dressing were consumed in one study. A substantially greater absorption of carotenoids was observed when salads were consumed with full-fat salad dressing than with reduced-fat salad dressing.
  • Sunflower oilSunflower oil: In human research, sunflower oil increased breast milk and plasma levels of beta-carotene (200).
  • Vitamin A-rich foodsVitamin A-rich foods: In human research, mortality significantly increased in patients using a combination of beta-carotene and vitamin A (78; 24).
  • Vitamin C-rich foodsVitamin C-rich foods: According to secondary sources, vitamin C affects the conversion of beta-carotene to vitamin A in the body.
  • Vitamin E-rich foodsVitamin E-rich foods: In human research, a combination of beta-carotene and vitamin E reduced the vitamin E concentration found in the normal colonic mucosa (103). In human research, mortality significantly increased in patients using a combination of beta-carotene and vitamin E (78).
  • Zinc-rich foodsZinc-rich foods: In pregnant women with night blindness and low serum zinc concentrations, zinc increased the effect of vitamin A in the restoration of night vision (201). According to secondary sources, zinc affects the conversion of beta-carotene to vitamin A in the body.

    • Beta-carotene/Lab Interactions:

  • CarotenoidsCarotenoids: In human research, beta-carotene increased blood levels of alpha-carotene and beta-cryptoxanthin (92).
  • Cell countsCell counts: In human research, beta-carotene lacked effect on HIV viral load, but CD4 counts increased (79). In human research, beta-carotene increased CD4 counts; these effects were lacking when beta-carotene was administered with a multivitamin (79).
  • Coagulation parametersCoagulation parameters: In human research, beta-carotene increased the risk of intracerebral hemorrhage in patients who also drank alcohol (145). According to secondary sources, unusual bleeding or bruising may occur.
  • CytokinesCytokines: In human research, beta-carotene decreased plasma levels of tumor necrosis factor (TNF)-alpha (193).
  • GlucoseGlucose: Although epidemiological research suggests that high serum levels of beta-carotene are associated with a reduced risk of developing type 2 diabetes and that impaired insulin sensitivity is associated with low serum beta-carotene (164), information from two randomized controlled trials included in a systematic review suggests that there is a lack of effect on beta-carotene on diabetes (119).
  • IronIron: In human research, beta-carotene improved anemia (121). In infants, iron supplementation increased vitamin A deficiency (91).
  • LipidsLipids: In human research, a combination of beta-carotene, selenium, and vitamins C and E decreased HDL2 in patients treated with simvastatin and niacin (109; 110). In human research, a combination of beta-carotene and vitamin A increased total cholesterol levels (111).
  • Liver enzymesLiver enzymes: In human research beta-carotene reduced alanine aminotransferase (ALT), aspartate aminotransferase (AST), and albumin, and increased levels of gamma-glutamyl transferase (GGT) and bilirubin (statistical significance unclear) (105).
  • LuteinLutein: In human research, beta-carotene supplementation lowered serum lutein concentrations (92). Also, in human research, lutein from a food source did not result in a decrease in beta-carotene concentrations that accompanied use of a lutein supplement (93).
  • RetinolRetinol: In human research, beta-carotene increased blood levels of retinol (92).