Since the 1930s, research (and some anecdotal wisdom) has shown that vitamin C (ascorbic acid) supplementation helps the body physiologically respond to heat stress. It reduces your likelihood of developing heat-related illnesses such as heat rash and heat exhaustion -- it can also be used to treat heat rash that's already developed. Daily vitamin C supplementation also shortens the length of time it takes your body to adjust to a new hotter environment, known as heat acclimatization. How? Possibly by reducing how fast your sweat glands tire out, but it's also shown to lower body (rectal) temperature [source: Ringsdorff, Kotze].
Preliminary research also indicates that vitamin C may be promising as a natural anti-histamine, as well as a powerful antioxidant. Vitamin C may help lessen the symptoms of seasonal allergic rhinitis, possibly most effective when combined not only with your current hayfever medication, especially with quercetin, a plant-derived flavonoid (you'll find it in red wine, tea and olive oil, as well as in berries and other darkly pigmented fruits and vegetables) that may help prevent your body from producing histamine.
Additionally, vitamin C's antioxidant effects may help the body protect itself from cell damage by encouraging the production of collagen and the growth of new tissue -- it also helps your tissue make repairs. These antioxidant benefits may help protect your skin from sun damage, including photoaging. Vitamin C is sometimes used topically to reduce the harmful effects of the sun's ultraviolet (UV) rays on the skin, and when you combine C with another vitamin -- vitamin E -- the pair may help prevent sunburns.
What else can vitamin E do for your summertime blues? Vitamin E has antioxidant benefits that help protect skin from UV damage when you use it topically before applying sunscreen, both before sun exposure and after you've been out in the sun.
Similar to the anti-allergy benefits vitamin C, when used with your existing seasonal allergy therapy, vitamin E may help reduce the severity of seasonal allergies (specifically nasal symptoms) and asthma. Vitamin E shows promise for calming the parts of the immune system that activate when you have an allergic response.
Just as vitamins C and E may offer relief for seasonal allergy sufferers, vitamin D also seems promising in helping to control asthma -- some early research indicates vitamin D's anti-inflammatory properties may help put the symptoms of asthma in check. What else can vitamin D do for you this summer? We'll talk more about the summertime benefits of vitamin D, as well as what vitamin A can do for you and your risk of skin cancer, next.