Vitamin B5 (Pantothenic Acid)

Vitaminas e minerais

Última revisão: 7 de abril de 2026. Abordagem de fontes: contexto padrão de interpretação laboratorial, material médico de referência e orientações clínicas ou de saúde pública quando relevantes.

O que é Vitamin B5 (Pantothenic Acid)?

Pantothenic acid, or vitamin B5, is a water-soluble vitamin that is an essential component of coenzyme A (CoA), one of the most important cofactors in human biochemistry. CoA participates in over 70 enzymatic pathways including the citric acid cycle, fatty acid synthesis and oxidation, amino acid metabolism, and the synthesis of cholesterol, steroid hormones, melatonin, and acetylcholine. Pantothenic acid is also a component of acyl carrier protein (ACP), which is required for fatty acid synthesis.

The name "pantothenic" derives from the Greek word "pantos" meaning "everywhere," reflecting its widespread presence in foods. Rich sources include organ meats, egg yolks, whole grains, avocados, broccoli, mushrooms, and legumes. Because of its ubiquity in the food supply, clinical deficiency is exceedingly rare in humans and is essentially limited to severe malnutrition. Pantothenic acid status can be assessed through blood levels, urinary excretion, or whole blood CoA levels, though these tests are rarely ordered in clinical practice due to the rarity of isolated deficiency.

Por que isso importa

As the precursor to coenzyme A, pantothenic acid sits at a metabolic crossroads—without it, the body cannot synthesize or break down fatty acids, cannot run the citric acid cycle for energy production, and cannot produce essential molecules like heme, cholesterol, and neurotransmitters. CoA is also required for the acetylation of proteins, a post-translational modification that regulates gene expression and enzyme activity. While clinical deficiency is rare, suboptimal B5 status may contribute to fatigue, impaired lipid metabolism, and adrenal insufficiency.

Faixas de referência normais

Grupo	Faixa	Unidade
Adults (whole blood)	1.6–2.7	µmol/L
Adults (urinary excretion)	>1.0	mg/day

As faixas de referência podem variar entre laboratórios. Sempre compare seus resultados com as faixas fornecidas pelo seu local de exame.

O que significam níveis altos de B5

Causas comuns

Supplementation with high-dose pantothenic acid
Megadose B-complex vitamins

Possíveis sintomas

Generally well-tolerated even at high doses
Diarrhea at very high doses (>10 g/day)
Gastrointestinal discomfort

O que fazer: No toxic upper limit has been established for pantothenic acid due to its excellent safety profile. At extremely high doses (>10 g/day), diarrhea and gastrointestinal distress may occur. Simply reduce supplementation if these symptoms appear. Excess is readily excreted in the urine.

O que significam níveis baixos de B5

Causas comuns

Severe malnutrition or fasting
Chronic alcoholism
Malabsorption syndromes
Extremely restrictive diets
Rare genetic disorders affecting CoA synthesis (pantothenate kinase-associated neurodegeneration)

Possíveis sintomas

Fatigue and malaise
Numbness and burning in feet ("burning feet syndrome")
Headaches
Irritability and restlessness
Sleep disturbances
Gastrointestinal distress (nausea, vomiting, abdominal cramps)
Impaired wound healing

O que fazer: Isolated pantothenic acid deficiency is extremely rare and usually indicates severe overall malnutrition. Treatment involves nutritional rehabilitation with a balanced diet and B-complex supplementation. Typical supplemental doses range from 5–10 mg daily. Burning feet syndrome historically responded to pantothenic acid supplementation in prisoners of war. Address underlying malnutrition and evaluate for concurrent vitamin deficiencies.

Quando o exame de B5 é recomendado?

Rarely ordered in clinical practice
When severe malnutrition is suspected
In evaluation of burning feet syndrome of unclear etiology
When pantothenate kinase-associated neurodegeneration (PKAN) is suspected
In research settings evaluating B-vitamin status comprehensively

Perguntas frequentes

The word "pantothenic" comes from the Greek "pantos" meaning "everywhere," and true to its name, vitamin B5 is found in virtually all foods. Meat, vegetables, grains, legumes, eggs, and dairy all contain meaningful amounts. The daily requirement is also relatively modest (5 mg for adults). The combination of widespread dietary availability and low requirements means that deficiency essentially only occurs in severe malnutrition or starvation conditions. In experimental settings, deficiency had to be induced using a specific metabolic antagonist.

Some practitioners and supplement manufacturers claim that high-dose pantothenic acid (5–10 g daily) can treat acne by increasing CoA availability and thereby enhancing fatty acid metabolism. While a few small studies have shown modest improvements in acne lesion counts with pantethine (a derivative), the evidence is limited and not well-established. More robust evidence supports the pantothenic acid derivative dexpanthenol (provitamin B5) as a topical agent for skin barrier repair and wound healing, which is why it appears in many skincare products.

Pantothenic acid is sometimes called the "anti-stress vitamin" because of its role in adrenal steroid hormone synthesis. The adrenal cortex has one of the highest concentrations of pantothenic acid in the body, and CoA is required for the synthesis of cortisol, aldosterone, and adrenal androgens from cholesterol. While this biochemical relationship is well-established, there is limited clinical evidence that supplemental B5 above the recommended daily intake improves adrenal function or stress resilience in well-nourished individuals.

Biomarcadores relacionados

B2Vitamin B2 (Riboflavin)B3Vitamin B3 (Niacin)PLPVitamin B6 B12Vitamina B12 FolateFolate

Leitura relacionada

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Referências e abordagem de revisão

As páginas do glossário de biomarcadores são explicações educativas e devem ser interpretadas junto com as faixas de referência e observações fornecidas pelo seu laboratório e pelo seu médico. Para conhecer nossos padrões editoriais e processo de revisão, veja nossa Política editorial e a nossa revisão de conteúdo.

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Aviso médico: Estas informações são apenas educativas e não substituem orientação, diagnóstico ou tratamento médico profissional. As faixas de referência podem variar entre laboratórios. Sempre converse com seu profissional de saúde sobre a interpretação dos seus resultados específicos.