When it comes to nutrition and fertility, more research has been done in the area of male infertility. It appears that certain vitamins and minerals affect the health and the motility of sperm. Attention has been paid to the antioxidant nutrients, in particular vitamin E, vitamin C and selenium. It is believed that free radicals, dangerous oxygen molecules found in the body, damage sperm. Antioxidants are able to neutralize these harmful chemicals, rendering them inactive in the body.
Two studies have found that vitamin E supplements, taken in doses of 100 and 200 international units (IU), improved sperm activity of infertile men and increased the rate of pregnancy in their partners.10 Preliminary research suggests that vitamin C may improve sperm count and sperm motility. Studies have also found that, compared to fertile men, infertile men have significantly lower levels of selenium in their semen.11 This would suggest that selenium plays a role in sperm development. And one Scottish study found that supplemental selenium improved sperm motility in men with low selenium levels.12
These studies are far from conclusive. But even if dietary antioxidants don’t improve your partner’s fertility, they are still important nutrients for you and your partner to be consuming in your diet, and quite possibly taking as supplements. Just read chapter 11, “Heart Disease and High Cholesterol” and you’ll understand their significance to health.
Here’s what your male partner needs to know:
• Vitamin C RDA is 90 milligrams (smokers need 125 milligrams). Best food sources include citrus fruit, citrus juices, cantaloupe, kiwi, mango, strawber- ries, broccoli, brussels sprouts, cauliflower, red pepper and tomato juice. To supplement, buy a 500- or 600-milligram supplement of Ester C; take once daily. The daily upper limit is 2000 milligrams.
• Vitamin E RDA is 15 IU (natural source) and 22 IU (synthetic). Best food sources include wheat germ, nuts, seeds, vegetable oils, whole grains and kale. To supplement, take 100 to 400 IU of natural source vitamin E. Buy a “mixed” vitamin E supplement if possible. The daily upper limit is 1000 IU.
• Selenium RDA is 55 micrograms. Best food sources are fish, seafood, chicken, organ meats, whole grains, nuts, onions, garlic and mushrooms. To supplement, take 200 micrograms per day. Check how much your multivitamin and mineral supplement gives you before you buy a separate selenium pill. The daily upper limit is 400 micrograms.
If your partner smokes cigarettes, encourage him to quit (same goes for you). Smoking causes the formation of those nasty free radical compounds that are thought to damage sperm. The damage caused by inhaling cigarette smoke is reflected in the higher recommended intake of vitamin C in smokers.
This vitamin may affect your partner’s fertility as well as your own. There is some evidence to suggest that a B12 deficiency may lead to lower sperm counts. One study looked at the effects of B12 supplements among infertile men.13 Supplementing the diet with extra B12 helped only those men with low sperm counts and impaired sperm motility. I realize this is not much to hang your hat on, but have your partner take a look at the B12-rich foods listed on page 10 in chapter 1, and make sure he includes more of them in his diet. Taking a multivitamin and mineral supplement is another simple way to prevent a deficiency.
This mineral is essential for growth, sexual development and sperm production. Many studies have found a link between infertility in men and low zinc concentration in seminal fluid. A zinc deficiency may also lead to low testosterone levels. In fact, one small study conducted in men with low testosterone levels found that zinc supplements increased sperm count and the rate of pregnancy in their partners.14
The RDA for zinc in men is 11 milligrams per day (women need 8 milligrams). The best food sources include oysters (a whopping 150 milligrams per 3 ounces!), dark turkey meat, lentils, ricotta cheese, tofu, yogurt, lean beef, wheat germ, spinach, broccoli, green beans and tomato juice. If supplements are used, take anywhere from 15 to 30 milligrams (many multivitamin and mineral formulas offer 15 milligrams). Make sure your zinc supplement has 1 milligram of copper since these two minerals work together. Too much zinc has toxic effects, so do not exceed 40 milligrams per day.
This compound is not considered an essential nutrient because the body makes it in sufficient quantities. Carnitine helps the body generate energy by transporting fat into cells. Most of our body’s carnitine is located in our muscles and heart, but a little is also found in the brain, liver and kidneys. It is also present in sperm and seminal fluid. A number of studies have found a positive relationship between sperm count and motility and their concentration of L-carnitine. The higher the concentration of L-carnitine, the higher the sperm count. Researchers have also found that infertile men have much lower levels of L-carnitine in their semen compared to fertile men.15
Does that mean that taking L-carnitine can improve male fertility? One Italian study addressed this. The findings revealed that 3 grams per day of L-carnitine taken for three months increased sperm count and sperm motility in 37 out of 47 men.16
L-carnitine is found in meat and dairy products. But you won’t get 3 grams of this natural compound from diet alone. If your partner decides to try a supplement, the recommended dose is 1 to 3 grams per day. Avoid products that contain D-carnitine or DL-carnitine. These forms compete with L-carnitine in the body and could lead to a deficiency. The supplement is considered safe. Occasional side effects of gastrointestinal upset have been reported.