Excerpt from Healthy Diet and Nutrition for Women
Beta-Carotene is the plant based, water soluble precursor to vitamin A, also known as provitamin A. It is found abundantly in fruits, vegetables and other plant sources. Once ingested, it is converted within the body to vitamin A, itself. This water soluble form is actually much safer than vitamin A itself, which is found in fish livers, whole milk, and eggs yolks and is fat soluble. Fat soluble vitamin A accumulates in the liver and can be toxic to the body at elevated levels. As a result, supplemental vitamin A intake needs to be kept at low levels, 5000 IU per day or less, with 2500 IU of daily intake being considered a good supplemental dosage.
The water soluble form, beta carotene, is much safer and can be ingested in much higher dosages, both in foods and taken as a supplement, without ill effects. The main side effect is the occasional appearance of orange coloring to the skin, especially the palms of the hands. The increased incidence of lung cancer has also been seen in chronic, high dosage consumption of beta carotene in smokers.
Beta carotene helps to improve female health in a number of ways. Deficiencies in vitamin A have been linked to benign breast disease, heavy menstrual bleeding, and skin aging. Because it is needed for healthy mucous membranes, a lack of vitamin A can worsen the signs of aging of the vagina and genitourinary tract after menopause.
Beta-carotene is abundant in the ovaries, and is found in very high concentrations in the corpus luteum of the ovary and the adrenal glands—both of which produce progesterone. After ovulation, the follicle that contained the egg that was expelled from the ovary during ovulation is then converted into a new structure called the corpus luteum. The purpose of the corpus luteum is to switch from the estrogen production, which predominates during the first half of the menstrual cycle (days 1 to 14) to the production of progesterone and estrogen during the second half of your cycle (days 15 to 28). This is called the luteinizing process. Some research studies even suggest that a proper balance between carotene and the retinal form of vitamin A is necessary for proper luteal function.
Researchers have been aware of the reproductive benefits of beta-carotene for more than a century. For example, cows whose diets were deficient in beta-carotene experienced delayed ovulation, decreased progesterone levels, and an increased prevalence of ovarian cysts, as well as cystic mastitis (breast cysts). Both conditions are typically found in women who are progesterone deficient.
Research studies have also found carotenoids such as beta carotene, as well as vitamin A, to be useful in treating conditions related to estrogen dominance, including ovarian cancer, heavy menstrual bleeding, and benign breast disease. A study from the International Journal of Cancer found that high carotenoid intake decreased a woman’s risk for ovarian cancer. In fact, beta-carotene rich carrots were among the foods most strongly associated with decreased risk.
Studies have also determined that vitamin A helps prevent heavy menstrual bleeding. Researchers tested the blood levels of 71 women suffering with excessive bleeding. They found that all the women had lower than normal levels of vitamin A. After taking vitamin A supplements for just two weeks, 90 percent of them returned to normal menstruation levels.
Finally, a study from Preventative Medicine found that high doses of vitamin A can help reverse one form of benign breast disease. Researchers gave 150,000 IU of vitamin A to 12 women with fibrocystic breasts. After three months, more than half the women reported complete or partial remission of the cysts. While I would never suggest that women take this high a dose of vitamin A for fear of toxicity, I believe that beta-carotene would have a similar effect.
Vitamin A is also essential for healthy skin and mucous membranes throughout the body. It is necessary for healthy immune function, resistance to infection, and healthy vision, especially the prevention of macular degeneration and cataracts. Vitamin A, as beta carotene, also helps to protect the body from developing many types of cancer, including cervical, lung, and bladder cancer. It also helps to protect the cardiovascular system from heart attacks and lowers the risk of strokes.
Clearly, beta carotene-containing fruit, vegetables and other plant foods should be eaten often for adequate intake of this essential nutrient. To ensure that you have adequate amounts of beta-carotene in your system, I suggest taking 5,000 IU a day or 10,000-25,000-000 IU a day if you are currently dealing with a health condition that would benefit from increased beta carotene intake. You can also eat foods rich in beta-carotene, such as spinach, squash, carrots, cantaloupe, pumpkin, and sweet potatoes.