The full answer
Yes — this is one of the most consistent effects of untreated celiac disease
Damage to the small intestine directly impairs absorption of key nutrients, commonly leading to deficiencies in iron, vitamin B12, folate, and fat-soluble vitamins like D and K — this is a major driver of symptoms like fatigue.
What follow-up usually looks like
Deficiencies often improve as the intestine heals on a gluten-free diet, but bloodwork is the only reliable way to confirm this — see why follow-up blood tests matter. Long-standing deficiencies can also affect bone density over time.
Important context
Individual symptoms, reactions, medical histories, food products, and local labeling rules can vary. Community experiences are not medical evidence.
For personal medical decisions, diagnosis, testing, or treatment, consult a qualified healthcare professional.