How long it takes for vitamins and supplements to work depends on factors like the type of vitamin, your diet and hydration, ...

So once you turn 40, consider getting extra B12 through a supplement or multivitamin. Aim for 2.4 to 2.8 micrograms per day (the recommended daily intake), though you generally don’t have to worry ...

Beta-carotene is responsible for the intense warm hues of many fruits and vegetables. Think: carrots, sweet potatoes, mangoes ...

Vitamins A and D are fat-soluble, which are stored in the body's fatty tissues and liver, says Kahn. Unlike water-soluble vitamins, which are excreted through urine, these can build up in the body.

A vitamin D test can help you see if you have a vitamin D deficiency. Learn about the best tests to buy here.

Eating fiber-rich foods daily is essential for maintaining a healthy gut and improving digestion. These foods help feed ...