Water-Soluble Vitamins: Videos & Practice Problems

Which of the following statements best summarizes the general properties of water-soluble vitamins?

A nutrition label lists vitamin B2, B6, B12 and vitamin C. A patient asks why these don't need to be taken with a fatty meal. Which explanation best reflects the absorption characteristic of these vitamins?

A patient has impaired pyruvate dehydrogenase activity causing difficulty converting pyruvate to acetyl-CoA. Which B vitamin deficiency is most directly implicated and why?

An elderly patient presents with fatigue and macrocytic anemia. He reports a varied diet including meat but has progressive dyspepsia and takes multiple antacids. Which storage/absorption explanation best accounts for risk of his possible B12 deficiency?

Which clinical presentation is most classically associated with thiamine (B1) deficiency?

A patient with pellagra-like symptoms (dermatitis, diarrhea, dementia) is suspected to have a deficiency in which vitamin, and what additional lipid effect would therapeutic doses of this vitamin have?

Riboflavin (B2) is required to form which coenzyme important for the electron transport chain and cellular respiration?

A 28-year-old woman planning pregnancy asks which vitamin form should be emphasized to reduce neural tube defect risk, and what is the difference between the dietary and supplemental forms?

Design a combined supplementation strategy to support an athlete’s increased energy metabolism that targets the coenzyme needs of carbohydrate and fat oxidation. Which combination of B vitamins is most appropriate and why?

A homeless patient with chronic alcoholism presents to clinic for confusion and ataxia. Which immediate nutritional intervention is highest priority and why?

Which of the following is NOT a recognized role of vitamin C (ascorbic acid)?

Why do very large daily doses of vitamin C often produce little additional benefit beyond recommended amounts?

A patient presents with macrocytic anemia and progressive peripheral neuropathy. Serum methylmalonic acid (MMA) is elevated and homocysteine is also elevated. Which deficiency is most likely and which dietary history detail would support this diagnosis?

Integrate your knowledge of B vitamin coenzymes: which set of vitamins provides cofactors required for transamination (amino acid interconversion), one-carbon transfers for nucleotide synthesis, and methylation reactions important in DNA synthesis?

Which water-soluble vitamin is stored in significant amounts in the liver and therefore may take years of poor intake before deficiency becomes clinically apparent?

Estimate how long it would take a strict vegan with no B12 intake to develop clinical deficiency assuming average liver B12 stores of 3000 µg and a physiological daily requirement (utilization/loss) of 2.5 µg per day. Show your calculation and final estimate in years.

Which triad of acute neurologic features is classically associated with Wernicke encephalopathy (related to thiamine deficiency)?

A patient presents with sore throat, swollen tongue, and dry cracked lips. Which B vitamin deficiency is most consistent with these signs and what is the coenzyme it helps form?

A patient who consumes raw egg whites daily develops hair loss, dermatitis, and lethargy. Which vitamin deficiency is most likely, and what is the biochemical mechanism linking egg white consumption to this deficiency?

Which diagnostic test and dietary/clinical history combination would best distinguish vitamin B12 deficiency from folate deficiency in a patient with macrocytic anemia and numbness in the feet?

Pantothenic acid (B5) is an essential component of which key coenzyme involved in fatty acid synthesis?

Which dietary change would most directly improve non-heme iron absorption for a person with borderline iron stores?

A 45-year-old patient reports chronic diarrhea, photosensitive dermatitis, and progressive cognitive decline. Their diet is heavily based on untreated corn-based porridge. Which deficiency best explains this triad and what is the biochemical basis?

Consider the metabolic fate of homocysteine: synthesize a clear explanation which single vitamin deficiency (from the B-complex) would most likely cause elevated homocysteine with normal methylmalonic acid (MMA) and why.

A patient shows macrocytic anemia but no neurologic symptoms. Folate levels are borderline low. Which is the best clinical evaluation and management approach to distinguish folate deficiency from B12 deficiency and to avoid harm?

Which B vitamin is particularly important for hemoglobin synthesis and can present with sore tongue, skin inflammation, and sometimes anemia when deficient?

Which of the following lists contains mainly excellent dietary sources of vitamin C?

A 60-year-old patient taking long-term proton pump inhibitors develops fatigue and paresthesias. You suspect B12 deficiency due to impaired absorption. Which laboratory pattern would best support this diagnosis?

Among the following patient scenarios, which one is at highest risk specifically for vitamin B12 deficiency and which preventive measure is most appropriate?