Preventing nutrient deficiencies while dieting involves consuming a varied and balanced diet. It's essential to include a wide range of whole foods such as fruits, vegetables, whole grains, lean proteins, and healthy fats. Paying attention to micronutrients like vitamins and minerals is important, particularly when following a calorie-restricted diet. Supplementation may be necessary for specific nutrients, particularly vitamin B12, iron, or calcium, depending on dietary restrictions. Consulting a healthcare professional or nutritionist can help create a plan that maintains essential nutrient intake while achieving weight loss goals.