Deficiency trapsB12: vegan/metformin/PPI/ileal disease + macrocytosis + neuropathy.
Thiamine: alcohol/vomiting/bariatric + confusion/ataxia/eye signs.
Vitamin C: bleeding gums, bruising, perifollicular hemorrhage.
Vitamin D: bone pain, proximal weakness, rickets/osteomalacia.
Toxicity trapsVitamin A in pregnancy is teratogenic.
Vitamin D/calcium excess causes hypercalcemia.
B6 excess causes sensory neuropathy.
Selenium excess causes hair/nail changes and garlic breath.
Zinc excess can cause copper deficiency.
Supplement safetyWarfarin/DOAC + high-dose fish oil, ginkgo, garlic, cranberry, turmeric, or vitamin E requires bleeding review.
St. John's wort and 5-HTP can contribute to serotonin toxicity.
Green tea extract, kava, black cohosh, and niacin can cause liver injury.
Therapeutic diet trapsDASH and Mediterranean patterns need individualization for CKD, potassium, diabetes, and food access.
Low-FODMAP requires reintroduction.
Celiac testing should occur while eating gluten when possible.
CKD products require sodium, potassium, phosphate, and protein review.