What is Vitamin A?

Vitamin A is an important fat-soluble vitamin that supports your immune system, vision, reproductive health, and fetal growth. Even though it’s essential to get enough, taking too much can be harmful.

Experts

Neuroscientist Dr. Andrew Huberman emphasizes the critical role of vitamin A in brain function, particularly in learning and memory, through its influence on synaptic plasticity. He also notes its importance in regulating circadian rhythms and supporting thyroid function, which are essential for cognitive performance and energy metabolism Significance of vitamin A to brain function, behavior and learning, Impacts of vitamin A deficiency on biological rhythms: Insights from the literature.

Dr. Paul Saladino, a carnivore diet advocate, points out that preformed vitamin A from animal sources is more bioavailable than plant-based carotenoids, which require conversion and may not be efficiently utilized by everyone Comparative bioavailability of vitamins in human foods sourced from animals and plants.

Nutrition expert Dr. Chris Masterjohn underscores the significance of vitamin A for maintaining healthy vision, skin, and immune function, and provides guidance on how to assess and manage one's vitamin A status through diet and supplementation Vitamin A by Chris Masterjohn.

Optimal

For optimizing brain function and energy, neuroscientist Andrew Huberman suggests a vitamin A intake of 3,000–10,000 IU daily, ideally from food sources like liver, eggs, and dairy, which exceeds the Recommended Dietary Allowance (RDA) of 3,000 IU for men and 2,333 IU for women aimed at preventing deficiency rather than boosting performance. However, he cautions that higher doses aren't universally ideal and exceeding 10,000 IU via supplements may risk toxicity, so consulting a healthcare professional is recommended to tailor this approach safely.

Pregnancy

For pregnancy, neuroscientist Andrew Huberman emphasizes that vitamin A intake should be carefully managed, with a recommended range of 2,500–3,000 IU daily from food sources like liver, eggs, and dairy, to support fetal development without exceeding the upper limit of 10,000 IU, as higher doses from supplements can pose risks like birth defects. This aligns with the Recommended Dietary Allowance (RDA) for pregnant women, which is 2,565 IU, aimed at preventing deficiency while ensuring safety for both mother and baby.

Recommended Dosage

Vitamin A intake is measured in micrograms (μg) of Retinol Activity Equivalents (RAE) or International Units (IU). The conversion is:

1 μg RAE = 3.33 IU of retinol (preformed vitamin A)
1 μg RAE = 10 IU of beta-carotene

Vitamin A is dangerous in high doses. Preformed vitamin A (retinol), Vitamin A from animal sources, the upper limit is 3,000 μg/day for adults. Women of reproductive age should be especially cautious with preformed vitamin A due to potential birth defect risks. There is no established upper limit for beta-carotene from food sources, as the body regulates its conversion to vitamin A.
Age Group	Nutrient Range
Infant (0-6 months) Adequate Intake (AI): 400 μg RAE/day Optimal range: 400 - 600 μg RAE/day Upper limit (UL): 600 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 400 600
Infant (7-12 months) Adequate Intake (AI): 500 μg RAE/day Optimal range: 500 - 600 μg RAE/day Upper limit (UL): 600 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 500 600
Child (1-3 years) Recommended (RDA): 300 μg RAE/day Optimal range: 300 - 600 μg RAE/day Upper limit (UL): 600 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 300 600
Child (4-8 years) Recommended (RDA): 400 μg RAE/day Optimal range: 400 - 900 μg RAE/day Upper limit (UL): 900 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 400 900
Child (9-13 years) Recommended (RDA): 600 μg RAE/day Optimal range: 600 - 1700 μg RAE/day Upper limit (UL): 1700 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 600 1700
Male (14-18 years) Recommended (RDA): 900 μg RAE/day Optimal range: 900 - 2800 μg RAE/day Upper limit (UL): 2800 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 900 2800
Male (19-50 years) Recommended (RDA): 900 μg RAE/day Optimal range: 900 - 3000 μg RAE/day Upper limit (UL): 3000 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 900 3000
Male (51+ years) Recommended (RDA): 900 μg RAE/day Optimal range: 900 - 3000 μg RAE/day Upper limit (UL): 3000 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 900 3000
Female (14-18 years) Recommended (RDA): 700 μg RAE/day Optimal range: 700 - 2800 μg RAE/day Upper limit (UL): 2800 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 700 2800
Female (19-50 years) Recommended (RDA): 700 μg RAE/day Optimal range: 700 - 3000 μg RAE/day Upper limit (UL): 3000 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 700 3000
Female (51+ years) Recommended (RDA): 700 μg RAE/day Optimal range: 700 - 3000 μg RAE/day Upper limit (UL): 3000 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 700 3000
Female (Pregnant) Recommended (RDA): 770 μg RAE/day Optimal range: 770 - 3000 μg RAE/day Upper limit (UL): 3000 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 770 3000
Female (Lactating) Recommended (RDA): 1300 μg RAE/day Optimal range: 1300 - 3000 μg RAE/day Upper limit (UL): 3000 μg RAE/day	300 μg RAE/day 3200 μg RAE/day 1300 3000

Summary

Optimal Intake (male 85kg/181cm / female 52kg/171cm)

Cognitive optimization male: 900-1200 μg RAE/day
Cognitive optimization female: 700-1000 μg RAE/day
Energy optimization male: 900 μg RAE/day (basic), up to 3000 μg RAE/day (athletic performance)
Energy optimization female: 700 μg RAE/day (basic), up to 3000 μg RAE/day (athletic performance)
Optimal intake for pregnancy: 770 μg RAE/day
Optimal intake for lactation: 1,300 μg RAE/day

Five best animal sources:

Beef liver: 85g (3 oz) provides 6,582 μg RAE (900 μg RAE RDA reached with 12g/0.4 oz)
Chicken liver: 85g (3 oz) provides 4,054 μg RAE (900 μg RAE RDA reached with 19g/0.7 oz)
Cod liver oil: 1 tsp (4.5g) provides 1,350 μg RAE (900 μg RAE RDA reached with 3g/0.7 tsp)
Eggs: 1 large (50g) provides 75 μg RAE (900 μg RAE RDA reached with 12 eggs)
Whole milk: 240ml (1 cup) provides 112 μg RAE (900 μg RAE RDA reached with 8 cups)

Five best non-animal sources:

Butternut squash: 205g (1 cup) provides 1,144 μg RAE (900 μg RAE RDA reached with 161g/0.8 cup)
Sweet potato: 128g (1 medium) provides 1,096 μg RAE (900 μg RAE RDA reached with 105g/0.8 med)
Spinach, cooked: 180g (1 cup) provides 943 μg RAE (900 μg RAE RDA reached with 172g/0.95 cup)
Kale, cooked: 130g (1 cup) provides 885 μg RAE (900 μg RAE RDA reached with 132g/1 cup)
Carrots: 72g (1 medium) provides 509 μg RAE (900 μg RAE RDA reached with 127g/1.8 med)

Consistent intake required? The body stores vitamin A in the liver, so strict daily intake is not essential. However, regular consumption is important for maintaining optimal levels. Dr. Huberman suggests consistency in intake is more valuable than occasional high doses.

Are higher doses dangerous? Yes, for preformed vitamin A (retinol), the upper limit is 3,000 μg/day for adults. Higher doses can cause toxicity symptoms. No established upper limit exists for beta-carotene from food sources, as the body regulates its conversion to vitamin A. Women of reproductive age should be especially cautious with preformed vitamin A due to potential birth defect risks.

Optimal timing for daily intake:

Morning: Consuming vitamin A-rich foods earlier in the day may better align with circadian rhythms
With meals: Take with dietary fats to enhance absorption
Consistency: Maintaining regular intake is more important than timing of individual doses
With synergistic nutrients: Vitamin A works best when consumed with zinc, vitamin D, and vitamin K2

Prenatal / Pregnancy / Lactation Summary

Vitamin A plays a crucial role during pregnancy and lactation, impacting both maternal health and fetal/infant development in numerous ways.

Why Vitamin A is Essential During These Periods

Embryonic development: Retinoic acid (active form of vitamin A) is critical for proper formation of the heart, central nervous system, eyes, and other organs during early embryonic development
Maternal immune function: Supports the mother’s immune system while it undergoes natural adaptation during pregnancy
Placental health: Contributes to healthy placental development and function
Fetal growth: Essential for proper cell differentiation and tissue formation throughout pregnancy
Visual development: Critical for developing the fetal visual system, including retina formation
Lung maturation: Helps in proper lung development and surfactant production
Brain development: Supports neurodevelopment and cognitive structures in the developing fetus
Milk production: During lactation, adequate vitamin A is needed for milk production and quality
Infant immunity: Vitamin A in breast milk supports the newborn’s developing immune system

Minimum and Optimal Requirements

Stage	Minimum Requirement	Optimal Intake Range
Planning Pregnancy	700 μg RAE/day	700-1000 μg RAE/day
Pregnancy	770 μg RAE/day	770-1500 μg RAE/day
Lactation	1,300 μg RAE/day	1,300-2000 μg RAE/day

Dr. Huberman notes that the increased needs during pregnancy and lactation reflect both maternal requirements and the demands of the developing baby or nursing infant.

Special Considerations and Genetic Factors

BCO1/BCMO1 Gene Variants: Unlike the MTHFR mutation affecting folate metabolism, variations in the BCO1/BCMO1 gene affect beta-carotene conversion to active vitamin A. Women with these variants (up to 45% of the population) may convert as little as 10-40% of plant-sourced beta-carotene to active vitamin A
Sources matter: Dr. Saladino emphasizes that women with BCO1/BCMO1 variants should prioritize preformed vitamin A from animal sources during preconception and lactation (while being careful with amounts during pregnancy)
Vitamin D relationship: Vitamin A works synergistically with vitamin D, another critical nutrient during pregnancy. Proper balance between these vitamins is essential
Zinc dependency: Vitamin A metabolism depends on adequate zinc levels, making zinc supplementation during pregnancy important for proper vitamin A utilization

Risks of Excessive Vitamin A During Pregnancy

Birth defects risk: Excess preformed vitamin A (retinol) during pregnancy, particularly in the first trimester, is strongly associated with birth defects affecting the central nervous system, cardiovascular system, and craniofacial structures
Safe upper limit: The upper limit during pregnancy is 3,000 μg RAE/day of preformed vitamin A, but research suggests limiting preformed vitamin A to under 2,500 μg RAE/day is safest during pregnancy
Animal liver caution: A single serving of beef liver contains approximately 6,500 μg RAE of preformed vitamin A, exceeding the upper limit. Pregnant women should limit liver consumption to small amounts (less than 50g/1.5 oz per week) or avoid it entirely during the first trimester
Supplement awareness: Many prenatal vitamins contain appropriate amounts of vitamin A, but women should avoid additional vitamin A supplements unless prescribed by a healthcare provider
Form matters: Beta-carotene from vegetables and fruits doesn’t pose the same risk as preformed vitamin A, as the body regulates its conversion

Practical Recommendations

Preconception: Ensure adequate vitamin A status before pregnancy, with a mix of preformed and provitamin A sources
During pregnancy: Focus on beta-carotene foods like sweet potatoes, carrots, and leafy greens, with modest amounts of preformed vitamin A from eggs, dairy, and very small amounts of liver if desired
During lactation: Increase intake through a combination of animal and plant sources to meet the higher demands of breastfeeding
Supplementation: Use only prenatal vitamins containing appropriate vitamin A levels, typically with more beta-carotene than preformed vitamin A
Testing: Consider testing vitamin A levels before pregnancy if following restrictive diets or if concerned about deficiency or excess

Introduction

Vitamin A is a group of fat-soluble compounds essential for vision, immune function, cellular communication, growth, and development. It exists in multiple forms:

Preformed Vitamin A (Retinoids): Found in animal foods and includes retinol, retinal, and retinoic acid
Provitamin A Carotenoids: Found in plant foods and converted to retinol in the body, with beta-carotene being the most efficient

The body stores vitamin A in the liver, and it can accumulate over time, which is important to consider when supplementing.

According to Dr. Paul Saladino, a carnivore diet advocate, preformed vitamin A from animal sources has superior bioavailability compared to plant carotenoids, which require conversion and can be inefficient in many individuals.

Effects at Different Vitamin A Levels

Optimal Levels

Sharp vision and night vision
Strong immune function with effective response to infections
Healthy skin and mucous membranes
Normal cell differentiation and gene expression
Proper reproduction and development
Healthy bone growth and development
Optimal brain function and neurotransmitter signaling
Balanced energy metabolism and cellular energy production

Deficiency

Night blindness (difficulty seeing in low light)
Dry eyes and increased infection risk
Impaired immune response and higher illness susceptibility
Follicular hyperkeratosis (rough, dry skin)
Slowed growth in children
Reduced fertility
Fatigue and reduced cellular energy production
Reduced cognitive function and altered neurological signaling

Severe Deficiency

Complete night blindness
Xerophthalmia (severe dry eyes)
Bitot’s spots (foamy buildup on the eye)
Corneal ulceration and scarring
Permanent blindness
Greatly increased mortality risk, particularly in children
Severe growth retardation
Major infections due to collapsed immune function
Profound fatigue and cognitive impairment

Toxicity (Excess)

Nausea, vomiting, headache, dizziness
Blurred vision and skin irritation
Bone and joint pain
Liver damage
Birth defects (if excess during pregnancy)
Hair loss
In extreme cases, increased intracranial pressure
Disrupted energy metabolism
Impaired cognitive function

Energy & Cognitive Benefits

Vitamin A plays crucial roles in energy production and brain function that are often overlooked.

Energy Metabolism

Mitochondrial Function: Vitamin A supports optimal mitochondrial function, the cellular powerhouses responsible for energy production. Research published in the Journal of Nutritional Biochemistry shows that vitamin A regulates mitochondrial ATP production.
Thyroid Hormone Activation: Dr. Andrew Huberman notes that vitamin A is required for proper thyroid function, which regulates your metabolic rate and energy levels.
Glycogen Storage: Supports proper glucose metabolism and glycogen storage in the liver, providing stable energy reserves.
Cellular Respiration: Influences the efficiency of oxygen utilization in cells, affecting overall energy production.

Cognitive Function

Neuroplasticity: Retinoic acid (a vitamin A metabolite) is involved in neuronal plasticity and helps form new neural connections.
Learning and Memory: Research in the Journal of Neuroscience demonstrates vitamin A’s role in spatial learning and memory formation.
Dopamine Regulation: Supports healthy dopamine signaling, important for motivation, focus, and reward.
Neuroprotection: Acts as an antioxidant in the brain, protecting neural tissue from oxidative damage.
Sleep Quality: Dr. Huberman points out that vitamin A helps regulate circadian rhythms, contributing to more restorative sleep and better daytime energy.

Recommended Dosage

Vitamin A intake is measured in micrograms (μg) of Retinol Activity Equivalents (RAE) or International Units (IU). The conversion is:

1 μg RAE = 3.33 IU of retinol
1 μg RAE = 10 IU of beta-carotene

General Recommendations

By Age Group

Age Group	Minimum Requirement
Infants (0-6 months)	400 μg RAE/day
Infants (7-12 months)	500 μg RAE/day
Children (1-3 years)	300 μg RAE/day
Children (4-8 years)	400 μg RAE/day
Children (9-13 years)	600 μg RAE/day
Adolescents male (14-18 years)	900 μg RAE/day
Adolescents female (14-18 years)	700 μg RAE/day
Adults male (19+ years)	900 μg RAE/day
Adults female (19+ years)	700 μg RAE/day
Pregnancy	770 μg RAE/day
Lactation	1,300 μg RAE/day

For Specific Body Types

Male (85kg, 181cm)

Standard RDA: 900 μg RAE/day
Adjusted for body weight: No standard adjustment needed, but those with higher body mass don’t necessarily need more vitamin A

Female (52kg, 171cm)

Standard RDA: 700 μg RAE/day
Adjusted for body weight: Standard dose is generally sufficient regardless of weight

The RDA is designed to meet the needs of 97-98% of healthy individuals and doesn’t typically need adjustment based on body weight alone. However, individual factors like diet, health conditions, and lifestyle may affect your personal needs.

Optimal Intake for Energy and Performance

Dr. Shawn Baker, a proponent of the carnivore diet, suggests that individuals consuming primarily animal foods may need less supplemental vitamin A, as animal sources provide the more bioavailable preformed vitamin A. However, those on restrictive diets should ensure adequate intake:

For optimal cognitive performance: 900-1200 μg RAE/day (staying within RDA for most individuals)
For athletic performance: Slightly higher intakes may benefit some athletes, but should remain below 3000 μg RAE/day from all sources
For energy optimization: Focus on consistency rather than maximum amounts - regular, moderate intake is key

Safe Upper Limits & Toxicity

Maximum Safe Dosage

Upper Intake Levels

Age Group	UL (μg/day of preformed vitamin A)
Infants (0-12 months)	600
Children (1-3 years)	600
Children (4-8 years)	900
Children (9-13 years)	1,700
Adolescents (14-18 years)	2,800
Adults (19+ years)	3,000
Pregnancy (14-18 years)	2,800
Pregnancy (19+ years)	3,000
Lactation	Same as pregnancy

For Specific Body Types

Male (85kg, 181cm)

Upper Limit: 3,000 μg/day of preformed vitamin A
This limit applies regardless of body weight

Female (52kg, 171cm)

Upper Limit: 3,000 μg/day of preformed vitamin A
Women of reproductive age should be especially cautious due to potential teratogenic effects

Note: These upper limits apply to preformed vitamin A (retinol) only, not beta-carotene from food sources. Beta-carotene supplementation may have separate concerns.

Dangerous Dose Levels

Acute Toxicity: Generally occurs at doses above 25,000-33,000 IU/kg (7,500-10,000 μg RAE/kg) taken at once
Chronic Toxicity: Can occur with daily intakes of 10,000-15,000 μg RAE over months or years
Pregnancy Concern: As little as 3,000 μg RAE daily may increase birth defect risk

Signs of Vitamin A Toxicity

Symptoms of hypervitaminosis A include:

Nausea and vomiting
Headache
Dizziness
Blurred vision
Skin irritation and peeling
Joint and bone pain
Liver damage
Birth defects (if taken during pregnancy)
Mental confusion and irritability
Fatigue and cognitive impairment

Health Effects and Benefits

Vision Health

Essential for night vision
Maintains conjunctival and corneal membranes
Helps prevent night blindness and xerophthalmia

Immune Function

Maintains integrity of mucosal surfaces that act as barriers
Supports production and function of white blood cells
Helps regulate immune responses
Dr. Paul Saladino notes that adequate vitamin A is crucial for appropriate immune function and may help prevent autoimmune issues

Cell Growth and Differentiation

Regulates gene expression
Critical for cell division and differentiation
Essential for proper organ development

Reproductive Health

Important for sperm production in men
Supports fetal development
Maintains integrity of reproductive tissues

Skin Health

Promotes skin cell production and turnover
Helps treat and prevent acne (as retinoic acid)
Prevents keratinization of epithelial tissues

Metabolic Health

Supports insulin sensitivity
Influences fat metabolism and storage
Dr. Shawn Baker highlights that vitamin A plays a role in optimizing hormone production, particularly in the context of animal-based diets

Brain Health and Performance

Supports neurotransmitter synthesis and signaling
Helps maintain neuronal health and communication
Dr. Andrew Huberman explains that vitamin A is critical for neural adaptation and learning
Influences dopamine system function, affecting motivation and drive

Deficiency Symptoms

Vitamin A deficiency can cause:

Night blindness (earliest symptom)
Xerophthalmia (dry eyes)
Bitot’s spots (foamy buildup on conjunctiva)
Keratomalacia (corneal ulcers and scarring)
Hyperkeratosis (rough, dry skin)
Impaired immunity and increased infection risk
Growth retardation in children
Reproductive issues
Mental fog and reduced cognitive function
Fatigue and reduced mitochondrial efficiency
Impaired stress resilience
Reduced athletic performance and recovery

Sources of Vitamin A

Food Sources with Amounts to Meet Requirements

Animal Sources (Preformed Vitamin A)

Food	Serving Size	Vitamin A Content (μg RAE)	Amount to Reach RDA (Male/Female)	Amount to Reach UL
Beef liver	85g (3 oz)	6,582	12g / 9g (0.4 oz / 0.3 oz)	39g (1.4 oz)
Chicken liver	85g (3 oz)	4,054	19g / 15g (0.7 oz / 0.5 oz)	63g (2.2 oz)
Cod liver oil	1 tsp (4.5g)	1,350	3g / 2.5g (0.7 tsp / 0.6 tsp)	10g (2.2 tsp)
Eggs	1 large (50g)	75	600g / 467g (12 eggs / 9.3 eggs)	2,000g (40 eggs)
Whole milk	240ml (1 cup)	112	1,929ml / 1,500ml (8 cups / 6.3 cups)	6,429ml (26.8 cups)
Cheddar cheese	28g (1 oz)	75	336g / 261g (12 oz / 9.3 oz)	1,120g (40 oz)
Butter	14g (1 tbsp)	97	130g / 101g (9.3 tbsp / 7.2 tbsp)	433g (31 tbsp)
Grass-fed meat	100g	10-20	9kg-4.5kg / 7kg-3.5kg	N/A
Salmon	100g	50-60	1.8kg-1.5kg / 1.4kg-1.2kg	50kg-60kg

Plant Sources (Provitamin A)

Food	Serving Size	Vitamin A Content (μg RAE)	Amount to Reach RDA (Male/Female)	Amount to Reach UL*
Sweet potato	128g (1 medium)	1,096	105g / 82g (0.8 med / 0.6 med)	N/A*
Carrots	72g (1 medium)	509	127g / 99g (1.8 med / 1.4 med)	N/A*
Spinach, cooked	180g (1 cup)	943	172g / 134g (0.95 cup / 0.74 cup)	N/A*
Kale, cooked	130g (1 cup)	885	132g / 103g (1 cup / 0.8 cup)	N/A*
Butternut squash	205g (1 cup)	1,144	161g / 126g (0.8 cup / 0.6 cup)	N/A*
Cantaloupe	160g (1 cup)	270	533g / 415g (3.3 cups / 2.6 cups)	N/A*
Mango	165g (1 cup)	181	820g / 638g (5 cups / 3.9 cups)	N/A*
Red bell pepper	149g (1 cup)	157	853g / 664g (5.7 cups / 4.5 cups)	N/A*

*Note: No Upper Limit has been established for beta-carotene from food sources, as carotenoid conversion to vitamin A is regulated by the body, preventing toxicity. However, high-dose beta-carotene supplements may have other concerns, particularly for smokers.

Carnivore Diet and Vitamin A

Dr. Paul Saladino and Dr. Shawn Baker highlight that a properly formulated carnivore diet can provide optimal amounts of vitamin A through:

Organ meats: Especially liver, consumed 1-2 times weekly provides abundant vitamin A
Egg yolks: Regular consumption supplies moderate amounts
Full-fat dairy: If included, provides additional vitamin A
Animal fats: Grass-fed sources contain small amounts that add up with consistent consumption

Dr. Saladino notes that the carnivore diet’s emphasis on preformed vitamin A (retinol) circumvents potential genetic variations that limit carotenoid conversion efficiency.

Supplements

Types of Vitamin A Supplements

Retinyl Palmitate/Acetate: Preformed vitamin A esters
Beta-carotene: Provitamin A carotenoid
Cod Liver Oil: Natural source of preformed vitamin A
Multivitamins: Often contain both preformed vitamin A and beta-carotene
Desiccated Liver Capsules: A whole-food source favored by ancestral health practitioners

Considerations When Choosing Supplements

Form: Preformed vitamin A carries a higher toxicity risk than beta-carotene
Dosage: Check the dose against the RDA and UL
Quality: Choose reputable brands with third-party testing
Interactions: Consider potential interactions with medications
Needs: Consider your diet and specific health needs
Synergistic nutrients: Look for supplements that include vitamin D, K2, and zinc for optimal absorption and utilization

Special Considerations

Pregnancy and Breastfeeding

Vitamin A is crucial for fetal development
Excessive preformed vitamin A can cause birth defects
Pregnant women should avoid high-dose supplements containing preformed vitamin A
Beta-carotene is generally considered safe during pregnancy

Medical Conditions Affecting Vitamin A

Liver disease: Impairs storage and metabolism
Fat malabsorption: Reduces vitamin A absorption
Zinc deficiency: Affects vitamin A transport and utilization
Alcohol use: Interferes with vitamin A metabolism
Hypothyroidism: May reduce conversion of beta-carotene to retinol

Medication Interactions

Retinoids (Accutane, Retin-A): Increases risk of toxicity
Orlistat: May decrease absorption
Cholesterol-lowering medications: May decrease absorption
Neomycin: May decrease absorption
Anticoagulants: May interact with high doses of vitamin A

Genetic Variations

Recent research has identified genetic variations that affect:

Beta-carotene conversion efficiency (BCMO1 gene)
Vitamin A transport and metabolism
Vitamin A receptor sensitivity

Dr. Saladino suggests that individuals with BCMO1 genetic variations may convert as little as 10% of dietary beta-carotene to active vitamin A, making animal-source retinol particularly important.

Optimizing Absorption and Utilization

Dr. Huberman highlights several factors that influence how effectively your body uses vitamin A:

Fat consumption: Consume vitamin A with dietary fats to enhance absorption
Zinc status: Ensure adequate zinc intake (oysters, red meat, pumpkin seeds)
Vitamin D levels: Maintain optimal vitamin D status for proper vitamin A function
Vitamin K2: Works synergistically with vitamins A and D (found in natto, cheese, grass-fed butter)
Protein adequacy: Required for vitamin A transport proteins
Gut health: Optimizing digestion improves absorption
Timing: Some evidence suggests vitamin A is better absorbed in the morning

Personalized Recommendations

For Male (85kg, 181cm)

Aim for the RDA of 900 μg RAE/day
Focus on obtaining vitamin A from a varied diet
If supplementing, consider a formula with more beta-carotene than preformed vitamin A
Don’t exceed 3,000 μg of preformed vitamin A from supplements and fortified foods
For optimal energy, include liver once weekly and egg yolks regularly
Consider desiccated liver capsules if you dislike the taste of fresh liver

For Female (52kg, 171cm)

Aim for the RDA of 700 μg RAE/day
If of reproductive age, be especially cautious with preformed vitamin A supplements
Choose beta-carotene as a safer form when supplementing
Ensure adequate protein and zinc intake to optimize vitamin A utilization
For cognitive enhancement, ensure consistent vitamin A intake alongside omega-3 fatty acids
If following a low-carb or carnivore approach, focus on egg yolks, small amounts of liver, and fatty fish

For Energy Optimization

Morning consumption: Dr. Huberman suggests consuming vitamin A-rich foods earlier in the day may align better with circadian biology
Pair with B vitamins: Combining vitamin A with B-complex vitamins supports mitochondrial energy production
Strategic timing: Consider slightly higher vitamin A intake during periods of increased cognitive demand
Consistency: Maintaining consistent intake is more important than occasional high doses

Summary

Vitamin A is an essential nutrient with critical roles in vision, immunity, cellular function, energy metabolism, and cognitive performance. While adequate intake is necessary, balancing intake is crucial as both deficiency and excess can cause health problems.

Getting Enough: Most people in developed countries can meet needs through diet
Avoiding Excess: Be cautious with supplements containing preformed vitamin A
Best Approach: Focus on food sources first, supplement only if needed
Monitoring: Watch for signs of deficiency or excess
Energy Optimization: Include regular vitamin A-rich foods for mitochondrial health
Cognitive Enhancement: Ensure consistent adequate intake to support brain signaling
Carnivore Approach: Focus on liver (1-2 times weekly), egg yolks, and grass-fed animal products

Remember that individual nutritional needs can vary based on health status, lifestyle, diet, and other factors. Consult with a healthcare provider before starting any supplement regimen.