Trace Minerals: Fluoride and Iodine: Videos & Practice Problems

Which of the following best describes fluoride's primary protective action in the oral environment?

A patient uses fluoride toothpaste but frequently grazes on acidic snacks. Which best explains why fluoride still reduces their caries risk despite frequent acid challenges?

Why are topical fluoride products (toothpaste, mouth rinse) designed to be spat out rather than swallowed?

A clinician must advise a patient who uses a high-fluoride prescription mouth rinse daily. Which rationale best uses the absorption routes to minimize systemic fluoride exposure while preserving oral benefits?

Which combination lists common sources of fluoride that contribute meaningfully to population intake?

A family drinks primarily bottled water and uses non-iodized specialty salts. Which practical recommendation best addresses potential fluoride needs for dental health?

Calculate an adult's daily fluoride intake given these daily items: 2 L/day fluoridated tap water at 0.7 mg/L, one cup brewed black tea contributing 1.0 mg, and accidental swallowing of 0.5 g toothpaste with 1000 ppm fluoride (1,000 µg fluoride per g). Determine total fluoride intake in mg and state whether it exceeds the typical adult RDA range of 3–4 mg.

A pediatric clinic reports several children with mottled enamel. You learn that children used to swallow a whole tube (75 g) of fluoride toothpaste with 1500 µg F/g when they were 3 years old. Assuming this occurred in a single incident, calculate the fluoride ingested in mg and analyze whether this single exposure explains fluorosis in permanent teeth (consider RDA context: adult 3–4 mg; children have lower tolerances).

Which is the most direct physiological consequence of iodine deficiency?

A pregnant patient reports using exclusively Himalayan salt and avoids iodized table salt. Which recommendation most directly reduces the fetus' risk of congenital hypothyroidism due to iodine deficiency?

Convert the iodine RDA of 150 µg and the UL of 1100 µg into milligrams, and determine whether a supplement containing 0.2 mg (200 µg) iodine taken daily would exceed the UL.

Which statement best explains why iodized table salt reduced the prevalence of iodine deficiency disorders?

A nutritionist evaluates a coastal population that switched from iodized table salt to sea salt and now shows a slight uptick in mild iodine deficiency. Which public-health recommendation best balances cultural preferences and iodine adequacy?

A region with high dental caries and historically mild iodine deficiency is designing policy. Which integrated strategy best synthesizes prevention of both issues while minimizing risks?

Which monitoring scheme most effectively balances the benefits of community water fluoridation and salt iodization while guarding against local increases in fluorosis and iodine excess?

A 6-year-old presents with diffuse white and brown mottling of permanent incisors but normal growth and TSH. Parents report frequent swallowing of fluoride toothpaste during early childhood. What is the most likely diagnosis and appropriate immediate counseling?

A child has pitted, discolored enamel and no other systemic findings. Another child has delayed growth and poor cognitive milestones with a history of a mother who avoided iodized salt during pregnancy. Which diagnostic tests most directly distinguish these two conditions?

Which of the following statements best evaluates the trade-off between community water fluoridation and the risk of dental fluorosis?

A community member drinks 3 L/day of water fluoridated at 1.2 mg/L, consumes 2 cups of tea daily contributing 1.6 mg each (total), and swallows small amounts of toothpaste adding 0.3 mg/day. Calculate their total daily fluoride intake and analyze whether it greatly exceeds the adult RDA range of 3–4 mg.

Design a short community outreach plan for neighborhoods where bottled water is the main drinking water and caries rates are high. Which combined elements create the most balanced, practical plan?

A consumer label reports iodine content of a seaweed snack as 2.5 mg per package. Which evaluation is correct regarding safety for daily consumption?

A low-income country must prioritize a single large-scale fortification project with limited funds. Considering both dental caries reduction and prevention of endemic goiter, which approach best synthesizes cost-effectiveness and population reach?

A nonpregnant adult presents with new onset dysphagia and a visibly enlarged midline neck mass. Their diet is low in iodine. Which evaluation is most appropriate to determine whether this represents an iodine-deficiency goiter versus another thyroid disorder?

A 45-year-old long-term resident of a highly fluoridated area presents with increasing bone stiffness. Lab and exposure history suggest chronic fluoride intake of approximately 8 mg/day for many years. Mechanistically, how can fluoride lead to increased bone mass and stiffness?

Compose a prioritized three-item clinical counseling script for an adult patient who drinks only well water (unfluoridated) and expresses concern about cavities. Which three elements, in order, best synthesize evidence-based preventive strategies?

A consumer takes a daily multivitamin with 150 µg iodine and eats a breakfast that provides 300 µg iodine, and occasionally consumes seaweed snacks providing an extra 800 µg about twice monthly. Which assessment is accurate regarding daily iodine safety?

Which salt choice is most likely to supply consistent iodine in a household diet without additional supplement use?

A mother reports her toddler swallowed a pea-sized amount (0.5 g) of 1000 ppm fluoride toothpaste twice daily for the past six months. Which immediate action and rationale best apply?

Calculate the daily fluoride shortfall for an adult who previously consumed 1.5 L/day of municipal water at 0.7 mg/L but now consumes only bottled water with negligible fluoride; then recommend the most direct mitigation to restore typical fluoride intake. Show the calculation and recommendation.

A breastfeeding mother obtains 250 µg/day iodine from diet, takes a prenatal supplement with 150 µg/day, and occasionally consumes a nutrition bar that contains 900 µg iodine once per week. Evaluate whether her average daily intake is safely below the UL of 1100 µg.