What vitamins help you deal with the summer heat?

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.

We know that vitamin D is good for our skin. It increases the skin's thickness, and thicker skin means fewer wrinkles, which is why vitamin D is a popular ingredient in anti-aging skin care remedies. Research has also found a link between our amount of sun exposure and how well our immune system is working, including our skin's immune defenses. Too little sun exposure and you risk developing a vitamin D deficiency. Too much sun exposure and you risk developing skin cancer. What surprised researchers in recent years, however, is that vitamin D3 may play a role in preventing cells from uncontrollably growing and dividing, which could protect us from certain cancers such as colorectal, breast and even skin cancer. In fact, a recent study discovered that when women took daily vitamin D supplements they had a 57 percent reduced risk of developing melanomas, a deadly form of skin cancer [source: RealAge]. But, Goldilocks, there is no recommendation for how much sun exposure is just right, so many doctors recommend supplements instead.

Vitamin A -- retinol -- may also help protect us from melanomas. Researchers studying vitamin A and its role in preventing skin cancer found that people who took daily vitamin A supplements (rather than relying on food intake) were 60 percent less likely to develop melanoma than those who didn't take supplemental retinol [source: Hazell].

Vitamin A helps your body repair sun-damaged skin, and may be one of the best options to combat the fine lines and hyperpigmentation of photoaging. In fact, if you use topical anti-aging products containing retinol, you may already know the benefits of vitamin A on your skin. Vitamin A comes in a few forms, and it's the compound form retinol that helps the body make needed repairs, including repairing sun-related cell damage and restoring collagen and elastin.