From the Research
To treat dark-colored toenails caused by nutritional deficiency, focus on addressing the specific deficiencies through dietary changes and supplements, prioritizing biotin, iron, and vitamin B12 deficiencies. The most common deficiencies causing nail discoloration are iron, vitamin B12, and biotin 1. Take an iron supplement (typically 65 mg elemental iron daily) if you have iron deficiency, along with vitamin C (500 mg) to enhance absorption. For B12 deficiency, take a supplement containing 1,000-2,000 mcg daily. Biotin supplements of 2,500-5,000 mcg daily can help strengthen nails and improve color, as biotin plays a crucial role in the treatment of diseases of cutaneous appendages and hyperseborrhea 2. Include iron-rich foods like lean meats, beans, and leafy greens; B12 sources such as eggs, dairy, and fortified cereals; and biotin-rich foods including eggs, nuts, and sweet potatoes in your diet.
Some key points to consider:
- Drink plenty of water and reduce alcohol consumption, which can interfere with nutrient absorption.
- Improvement typically takes 3-6 months as nails grow slowly.
- If discoloration persists after 2-3 months of supplementation, consult a healthcare provider to rule out other causes like fungal infections or underlying health conditions.
- Nutritional deficiencies affect nail appearance because nutrients are essential for keratin production and healthy nail growth 3, 4.
- The use of biotin is rationale in treating nail disorders, and its administration may improve the treatment of nail diseases when deficiency is detected 2.
It is essential to note that while multiple studies support the role of biotin, iron, and vitamin B12 in treating nail disorders, the most recent and highest quality study 2 prioritizes biotin supplementation in the treatment of diseases of cutaneous appendages and hyperseborrhea.