A 42-year-old man with uncontrolled type 2 diabetes visited the clinic complaining of persistent fatigue, tingling sensations in his hands and feet, and difficulty walking. These symptoms indicated that his high blood sugar levels were starting to damage his nerves—a condition known as diabetic neuropathy. His HbA1c test, which measures average blood sugar over the past three months, was 9.2 percent, confirming poor diabetes control. However, what surprised the medical team was the discovery of severe deficiencies in his vitamin levels: vitamin B12 measured at 123 pg/mL (severely deficient), vitamin D3 at 8 ng/mL (deficient), and magnesium at 1.5 mg/dL (low).
Upon further investigation, it became clear that the man had been taking Metformin, a common diabetes medication, for several years without any vitamin B12 supplementation. Metformin is known to interfere with vitamin B12 absorption over long periods. Additionally, the patient’s diet lacked essential nutrients as he avoided dairy and fruits, mistakenly believing these foods would worsen his blood sugar levels.
After initiating vitamin B12 injections and vitamin D supplementation, alongside dietary improvements and better diabetes management, the patient showed significant relief from neuropathy symptoms within four months. His fatigue reduced, and the tingling and numbness in his extremities improved noticeably.
This case highlights an important lesson for diabetes management: monitoring blood sugar levels alone is not enough. Vitamin and mineral deficiencies, especially vitamin B12 and vitamin D, can mimic or worsen diabetic complications like neuropathy. Diabetes itself may impair nutrient absorption, increasing the risk of micronutrient deficiencies over time.
Such deficiencies, if left unaddressed, can exacerbate problems such as poor wound healing, nerve damage, and cardiovascular complications. Therefore, regular screening for vitamin deficiencies should be considered an integral part of diabetes care. Ensuring proper nutrition, supplementation when necessary, and medication review can help reduce complications and improve the quality of life for diabetic patients.
