The recommended vitamin D strength to take depends on your age and health status. For most adults aged 19 to 70 years, a daily dose of 600 IU (15 mcg) is generally recommended to maintain adequate vitamin D levels and support bone and overall health. Adults over 70 years are usually advised to take 800 IU (20 mcg) daily. Some health experts suggest that 1,000 to 2,000 IU per day is safe and may offer additional benefits, but doses higher than 4,000 IU per day should only be taken under medical supervision to avoid toxicity. If you have a vitamin D deficiency, your healthcare provider might prescribe higher doses temporarily. It is best to consult with a healthcare professional for personalized advice, especially if you have underlying health conditions or take other medications.