Nutrition and Environmental Medicine Quiz

Questions and Answers

Which method is considered the most reliable for assessing dietary intake of pantothenic acid?

Blood levels

Urine levels (correct)

Plasma levels

Serum levels

What is the recommended daily allowance (RDA) of biotin for adults?

8 µg

30 µg (correct)

12 µg

20 µg

Which food source is NOT a recognized source of biotin?

Liver

Soybean products

Egg yolk

Beef (correct)

What is the standard oral dosage for pantothenic acid treatment?

5 mg/day Signup and view all the answers

Which of the following actions is NOT associated with biotin?

Cofactor for protein synthesis Signup and view all the answers

What are the potential chronic effects of excessive vitamin C intake?

Increased risk of kidney stones Signup and view all the answers

What is the recommended daily intake of vitamin C for adults to prevent scurvy?

60 mg Signup and view all the answers

Which of the following foods should be encouraged for high vitamin C intake?

Citrus fruits and green peppers Signup and view all the answers

What is the management approach when vitamin C toxicity is suspected?

Ascorbic acid at 100 mg 3-5 times a day Signup and view all the answers

Which condition has inconclusive evidence regarding the protective role of vitamin C in its management?

COVID-19 pneumonia Signup and view all the answers

What is a rare cause of biotin deficiency?

Consumption of large amounts of raw egg whites Signup and view all the answers

Which symptom is associated with biotin deficiency?

Dermatitis around the eyes, nose, and mouth Signup and view all the answers

Which of the following is a sign of vitamin C deficiency?

Bleeding gums and scurvy Signup and view all the answers

What is the recommended treatment for biotin deficiency?

Biotin in the dose of 10 mg/day Signup and view all the answers

Where is vitamin C primarily absorbed in the body?

Distal small intestine Signup and view all the answers

What is the significance of NAD and NADP in biochemical reactions?

They serve as cofactors for many enzymatic redox reactions. Signup and view all the answers

Which food source is NOT rich in vitamin B3 (niacin)?

White bread Signup and view all the answers

How much tryptophan is needed to produce 1 mg of niacin?

60 mg Signup and view all the answers

What is the Recommended Dietary Allowance (RDA) for niacin in adult females?

14 mg Signup and view all the answers

Which of the following is NOT a known cause of pellagra?

Excess vitamin B6 Signup and view all the answers

How does the body convert tryptophan into niacin?

Via a complex process requiring vitamin B6. Signup and view all the answers

Which condition is associated with diversion of tryptophan metabolism away from niacin production?

Pheochromocytoma Signup and view all the answers

What does the term 'pellagra' literally translate to?

Raw skin Signup and view all the answers

What are the four primary clinical features associated with Pellagra?

Dermatitis, diarrhea, dementia, death Signup and view all the answers

Which skin manifestation is specifically associated with Pellagra?

Casal's necklace Signup and view all the answers

What gastrointestinal symptoms are typically seen in Pellagra?

Diarrhea and nausea Signup and view all the answers

What kind of neurological symptoms may occur in severe cases of Pellagra?

Hallucinations and acute psychosis Signup and view all the answers

How is the diagnosis of Pellagra confirmed?

Assessment of clinical features and response to nicotinamide Signup and view all the answers

What is the typical treatment regimen for someone diagnosed with Pellagra?

Nicotinamide 100-200 mg three times daily Signup and view all the answers

What is a rare clinical manifestation of Pantothenic acid deficiency?

Burning feet syndrome Signup and view all the answers

Which dietary sources are rich in pantothenic acid?

Egg yolk, liver, and broccoli Signup and view all the answers

What is the recommended dietary intake for pantothenic acid for adult men and women?

5 mg daily Signup and view all the answers

What condition may present in mild deficiency of pantothenic acid?

Muscle cramps and depression Signup and view all the answers

What is the primary cause of scurvy?

Deficiency of vitamin C Signup and view all the answers

Which population is at the highest risk of vitamin C deficiency?

Infants exclusively fed boiled cow's milk Signup and view all the answers

Which of the following is NOT a symptom of adult scurvy?

Scorbutic rosary Signup and view all the answers

What characterizes hemorrhages in scurvy?

Spontaneous bleeding in various organs Signup and view all the answers

What is a reliable laboratory finding for diagnosing vitamin C deficiency?

Leukocyte vitamin C levels Signup and view all the answers

Which condition requires increased intake of vitamin C?

Thyrotoxicosis Signup and view all the answers

What symptom can be observed in both adult and infantile scurvy?

Delayed wound healing Signup and view all the answers

Which of the following is typically associated with infantile scurvy?

Subperiosteal hemorrhage Signup and view all the answers

Which dietary habit increases the risk of vitamin C deficiency in the elderly?

Not eating vegetables Signup and view all the answers

What is a common cutaneous presentation of scurvy?

Perifollicular hemorrhages Signup and view all the answers

Study Notes

Pantothenic Acid (Vitamin B5)

Diagnosis involves evaluating blood, plasma, serum, or urine levels; urine levels preferred for dietary intake assessment.
Management includes a daily oral dosage of 5 mg of pantothenic acid.

Biotin

Key sources: Liver, egg yolk, soybean products, yeast.
Essential cofactor for carboxylase enzymes in carbohydrate, amino acid, and lipid metabolism.
Recommended daily allowance (RDA): 8-12 µg daily for children, 30 µg daily for adults.

Vitamin B3 (Niacin)

Sources include yeast, meats (especially liver), grains, legumes, corn, and seeds.
Tryptophan can be converted to niacin; requires 60 mg tryptophan for 1 mg niacin along with vitamin B6.
NAD/NADP function as cofactors in enzymatic redox reactions.
RDA is measured as niacin equivalents (NE): 6-12 mg for children, 16 mg for adult males, and 14 mg for nonpregnant females.

Pellagra

Caused by niacin deficiency, resulting in a metabolic encephalopathy.
Common in regions where corn is a major dietary staple, such as parts of China, Africa, and India.
Four D's of Pellagra: Dermatitis, Diarrhea, Dementia, Death, although not always observed.
Skin manifestations include Casal's necklace, with rashes developing from sun exposure.

Causes of Pellagra

Inadequate intake from maize or jowar diets, malnutrition, chronic alcoholism.
Rare generalized malabsorption.
Drug-induced causes (e.g., prolonged isoniazid therapy, certain chemotherapeutics).
Other disorders, such as Hartnup's disease or carcinoid syndrome, divert tryptophan away from niacin production.

Vitamin C (Ascorbic Acid)

Toxicity can be acute or chronic; acute toxicity linked to doses over 2g, causing abdominal issues.
Chronic effects may include kidney stones, iron overload, hemolysis in G6PD deficiency, and interference with drug efficacy.
Recommended dietary intake: 120 mg daily for adults, with 60 mg required to prevent scurvy.
High Vitamin C intake may lower the incidence of gastric and esophageal cancers.

Clinical Features of Pellagra

Chronic deficiency can lead to skin, gastrointestinal, and neurological symptoms.
Dermatological symptoms include hyperpigmentation and skin lesions.
Gastrointestinal issues can manifest as diarrhea, glossitis, and dysphagia.
Neurological symptoms range from depression to hallucinations and confusion.

Diagnosis and Management

Diagnosis reliant on clinical features; rapid improvement with niacin treatment is notable.
Niacin status is assessed through urinary metabolites or erythrocyte NAD:NADP ratios.
Treatment for niacin deficiency typically includes nicotinamide at 100-200 mg, with dietary changes recommended.

Vitamin B12 and Folic Acid

Further details addressed in Chapter 8.

Biotin Deficiency

Rare but can arise from long-term parenteral nutrition or excessive raw egg white consumption.
Clinical symptoms may include dermatitis, conjunctivitis, and neurological changes.
Diagnosis involves measuring urine biotin concentrations and enzyme activity.

Vitamin C Deficiency (Scurvy)

Scurvy is primarily due to insufficient Vitamin C intake.
High-risk groups include infants on inadequate diets, individuals with chronic diseases, and those lacking vegetable intake.
Symptoms of scurvy comprise malaise, weakness, hemorrhages, and emotional changes.

Scurvy Types and Symptoms

Adult scurvy: Symptoms include fatigue, pain, easy bruising, and bleeding gums.
Infantile scurvy (Barlow's disease): Notable for subperiosteal hemorrhages and skeletal changes.

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Description

Test your knowledge on pantothenic acid and biotin, two essential vitamins crucial for metabolic functions. This quiz covers their diagnostic methods, management, and dietary sources. Perfect for students and professionals in nutrition and health sciences.