It really depends. Many factors are at play, including our state of health, age, skin tone, and diet. If you’re deficient, you would want to take a higher dose. Children aged 1 to 10 years should not have more than 50 micrograms (2,000 IU) a day. Infants under 12 months should not have more than 25 micrograms (1,000 IU) a day. The dose safe for all ages is 10 micrograms (400 IU) per day. Before supplementing with vitamin D, it’s wise to find out your levels with a vitamin D test kit (super easy to take yourself at home!), or speak with your GP or nutritionist for tailored advice.