The recommended daily intake of vitamin B complex varies by the specific B vitamin and individual factors such as age, sex, and health conditions. For adults, general daily recommendations are approximately:

• Vitamin B1 (Thiamine): 1.1 mg for women, 1.2 mg for men
• Vitamin B2 (Riboflavin): 1.1 mg for women, 1.3 mg for men
• Vitamin B3 (Niacin): 14 mg for women, 16 mg for men
• Vitamin B5 (Pantothenic acid): 5 mg
• Vitamin B6 (Pyridoxine): 1.3 mg for most adults
• Vitamin B7 (Biotin): 30 micrograms (mcg)
• Vitamin B9 (Folic acid): 400 mcg
• Vitamin B12 (Cobalamin): 2.4 mcg

These values can be higher for pregnant or breastfeeding individuals or older adults. It's important to get a balance of all B vitamins, often achieved through a B-complex supplement or a varied diet. Following the dosage instructions on the supplement label and consulting a healthcare provider for personalized advice is recommended, especially for those with medical conditions affecting B vitamin absorption.