Beta-carotene in foods is converted to vitamin A in the body, and vitamin A is necessary for all cell growth, including hair. A deficiency can lead to dry, dull, lifeless hair and dry skin, which can flake off into dandruff. Be aware that you can have too much of a good thing when it comes to vitamin A: Too much can cause hair loss. My advice is to add more beta-carotene-rich foods like sweet potatoes, carrots, kale, butternut squash, cantaloupe, dark green lettuces, asparagus, and pumpkin to your meals rather than take vitamin A supplements. If you should choose to take a multivitamin, check the label to make sure that your brand supplies no more than 50 percent DV of vitamin A in the form of retinol. Retinol is listed on supplement labels as palmitate or acetate, and should never exceed 2,000 IU. The other 50 percent or more should come in the form of beta-carotene (or carotenoids), which is converted to vitamin A only as we need it.