Lever
Lifestyle
- Regular monitoring of vitamin intake
- Avoid excessive alcohol consumption
- Maintain a balanced diet
Blutwerte · Marker
Vitamin A
Retinol · Vitamin A · Retinyl Palmitate
Vitamine & NährstoffeNüchtern erforderlich
- Einheit:
- µmol/L
- Abbreviation
- Retinol
Vitamin A tests measure the concentration of retinol in the blood, reflecting the body's vitamin A status.
Reference Ranges
Reference
0.7–2.8µmol/L
0.7
2.8
LowNormalHigh
Reference
Unit · µmol/LRanges may vary slightly based on age and sex; fasting recommended for accurate assessment.
Overview
Übersicht
Vitamin A, also known as retinol, is a fat-soluble vitamin essential for various biological functions, including vision, immune function, and cellular communication. It exists in several forms, with retinol being the most active. Vitamin A is crucial for the differentiation of epithelial tissues and is involved in the regulation of gene expression. Clinically, vitamin A levels are significant as they can reflect nutritional status and are associated with conditions such as night blindness, immune deficiencies, and skin disorders. Deficiency is rare in developed countries but can lead to severe health issues, while excess intake can result in toxicity, affecting liver function and causing symptoms like headache and dizziness. For athletes and biohackers, maintaining optimal vitamin A levels is important for supporting immune function and skin health, which can be beneficial for recovery and overall performance. However, researchers have observed that vitamin A metabolism can be influenced by factors such as diabetes, which may alter its levels in the body. It is important to consider confounding factors such as dietary intake, liver health, and the presence of other fat-soluble vitamins when interpreting vitamin A levels. Testing should ideally be done in a fasted state to avoid postprandial variations.
Klinische Bedeutung
Elevated vitamin A levels can indicate hypervitaminosis A, often due to excessive supplementation, leading to liver damage and other toxic effects. Reduced levels suggest deficiency, which can cause night blindness, immune dysfunction, and skin issues.
Dynamics
Trend Interpretation
Rising Values
Progressively rising values may suggest excessive intake or liver dysfunction. Re-test in 4 weeks if levels are high.
Falling Values
Progressively falling values may indicate dietary insufficiency or malabsorption.
Re-test Interval
4 weeks if outside optimal range
Etiology
Causes — High & Low
Cause
Elevated Levels
- Excessive supplementation
- High dietary intake
- Liver disease
- Renal failure
- Certain medications
Cause
Low Levels
- Poor dietary intake
- Malabsorption syndromes
- Liver disorders
- Chronic alcoholism
- Zinc deficiency
Protocol
How to Optimize
Lever
Nutrition
- Include liver and fish in diet
- Consume orange and yellow vegetables
- Eat leafy green vegetables
Lever
Supplementation
- Retinol supplements
- Beta-carotene supplements
Note:
Consult a healthcare provider before starting supplements, especially if pregnant or having liver conditions.
Testing Guidelines
🍽️Fasting Required
✓Not Time-Sensitive
Testing Frequency
Annually for adults, more frequently if at risk of deficiency or toxicity.
Interfering Factors
- Recent high-fat meal
- Alcohol consumption
- Certain medications
Related Peptides & Hormones
Insulin
hormone or peptideMay affect
Open Research Questions
Current research suggests that the relationship between vitamin A levels and type 2 diabetes remains uncertain, particularly regarding optimal targets for vitamin A intake and its metabolic impacts. Researchers have not yet established clear reference ranges for vitamin A in the context of neurodegenerative diseases, despite its potential neuroprotective effects. Additionally, unanswered clinical questions include the precise role of vitamin A in diabetic complications and the long-term effects of vitamin A supplementation in various populations.
25 Research Publications
932
Total Citations
5
Human/RCT
3.4
Avg. Influence
2025
Latest
Sort
Filter
01Top
#01
Vitamin a deficiency and clinical disease: an historical overview.
ReviewInfluence8.0
305
Researchers provided a historical overview of vitamin A deficiency and its clinical manifestations. They noted that vitamin A deficiency can lead to severe health issues, including xerophthalmia and increased susceptibility to infections, emphasizing its global health impact.
02Top
#02
Assessing vitamin A status: past, present and future.
ReviewInfluence5.0
183
This study reviewed methods for assessing vitamin A status, noting that traditional eye signs are less effective for identifying subclinical deficiency. Researchers highlighted the importance of considering infection effects on serum retinol levels when evaluating vitamin A status.
03Top
#03
Retinoids in biological control and cancer.
ReviewInfluence5.0
116
Researchers reviewed the relationship between vitamin A deficiency and cancer, establishing a link between retinoids and tumor prevention. The study emphasized the need for continued research on retinoid signaling pathways for therapeutic applications.
04
#04
Vitamin A deficiency disorders: international efforts to control a preventable "pox".
ReviewInfluence2.0
111
This review addressed global efforts to control vitamin A deficiency disorders (VADD), which affect millions. Researchers noted that while progress has been made through supplementation and food fortification, sustainable strategies are essential for long-term success.
05
#05
Lipophilic antioxidants in neurodegenerative diseases.
ReviewInfluence2.0
48
This review explored the potential role of lipophilic antioxidants, including vitamin A, in neurodegenerative diseases. Researchers found that while clinical evidence is lacking, laboratory studies suggest a relationship between these antioxidants and neuroprotection. Future studies are needed to optimize treatment strategies.
06
#06
Changes in micronutrient and inflammation serum biomarker concentrations after a norovirus human challenge.
Human
38
In a study involving healthy adults exposed to norovirus, researchers observed that inflammation affected serum concentrations of several micronutrient biomarkers, including vitamin A. Specifically, retinol levels were found to be depressed during the inflammatory response following infection.
07
#07
Oral contraceptives and vitamins: a review.
ReviewInfluence1.0
33
This review examined the effects of oral contraceptives on vitamin levels, noting that elevated vitamin A levels may not have clinical significance. Researchers found connections between hormonal contraception and disturbances in vitamin B6 metabolism, but hematologic abnormalities are rare.
08
#08
Vitamin A derivatives in the prevention and treatment of human cancer.
Review
32
This report discussed the role of vitamin A and its derivatives in cancer prevention and treatment. Researchers found that while natural vitamin A has limited activity against cancer, synthetic retinoids show promise in treating various malignancies.
09
#09
Vitamin A and Diabetes.
Review
26
Researchers summarized the relationship between vitamin A and diabetes, noting that type 1 diabetes is associated with reduced blood vitamin A levels. They also found that the effects of type 2 diabetes on vitamin A metabolism remain uncertain. The study highlights the need for further research to clarify these interactions.
10
#10
The Clinical Significance of Urinary Retinol-Binding Protein 4: A Review.
Ratajczyk Krzysztof, et al. · International journal of environmental research and public health · 2022
Review
20
Researchers reviewed the potential of urinary retinol-binding protein 4 as a biomarker for renal diseases. They found that it is a sensitive indicator of renal tubular damage, suggesting its promise for early diagnosis and monitoring of renal pathologies.
Key findings
- 01Urinary retinol-binding protein 4 is the most sensitive indicator of renal tubular damage.
- 02It shows potential as a universal biomarker for kidney diseases driven by tubular injury.
- 03The review emphasizes the need for further exploration of its clinical applications.
Publication Trend
Research publications about Vitamin A over time
9totalTrack your bloodwork in PepStack
Log lab results, track trends and optimize your biomarkers over time.
Legal Disclaimer
This page is for informational and research purposes only. All information is based on published scientific literature and does not constitute medical advice, diagnosis, or treatment recommendations. Many substances listed may not be approved for human use and may be subject to drug regulation laws (e.g., AMG in Germany, FDA in the US). PepStack does not encourage the use of any substance on humans. Always consult a qualified healthcare professional before making any health-related decisions. Use of this information is entirely at your own risk. PepStack assumes no liability for the accuracy, completeness, or timeliness of the content provided. Full disclaimer