Roughly one in three adults carries a specific nutritional deficiency - most often vitamin D, iron, vitamin B12, folate or magnesium. These are not the dramatic textbook deficiencies; they're the low-grade, chronic ones that quietly persist for years without a clear symptom. Frank malnutrition is rare in Singapore, but limited sun exposure, plant-heavy diets, gut absorption issues, alcohol use and certain medications steadily drain micronutrient stores. Sub-clinical vitamin D deficiency alone is linked to higher risk of diabetes, cardiovascular disease, cancer and chronic inflammation. The only reliable way to know what your body is actually short of - rather than guessing with a supplement shelf - is a structured screen with the right blood tests, interpreted by a doctor.