Not every vitamin or mineral supplement is good for your health, especially when the dosage is high. All the micronutrients (vitamins and minerals) are necessary to health. But in excessive amounts any nutrient might be harmful.
For my own preps and health, I consider zinc to be an important supplement. The US RDA for zinc is 8 mg/day for adult women and 11 mg/day for adult men. But it’s difficult to get enough zinc from food alone on a daily basis. Pumpkin seeds and sesame seeds (or sesame tahini) are each among the best sources of zinc. But you would have to eat about 3.5 oz/day to get 10 to 11 mg (USDA data).
On the other hand, some studies have indicated that a moderate dose of zinc from supplements can help prevent certain diseases.
A study published in 2007 in the American Journal of Clinical Nutrition found that “Zinc supplementation decreases incidence of infections in the elderly“. The dosage in that study was 45 mg of zinc per day. Participants were followed for one year.
In that time, the 88% of the placebo group had some type of infection, compared to only 29% of the zinc group. None of the members of the zinc group had more than one infection, whereas 24% of the placebo group had two infections, 8% had three, and 4% had four. Only 8% of the zinc group needed antibiotics in that year, compared to 48% of the placebo group. There were no incidents of tonsillitis, cold sores, flu, or fever in the zinc group. But 20% of the placebo group had fever, 12% had the flu, 12% had cold sores, and 8% had tonsillitis. The common cold afflicted 16% of the zinc group, compared to 40% of the placebo group.
One of the top concerns of prepping is preparing for, and dealing with, outbreaks of infectious diseases. Zinc supplements can be one way to decrease your risk of infection, at least for some types of illness.
There is a problem, though, with many supplements on the market today. They offer an amount of each vitamin or mineral far in excess of a healthy dosage. How much zinc is excessive? One study, published in the Journal of the National Cancer Institute (Leitzmann 2003), found that zinc supplementation in excess of 100 mg/day increased the risk of prostate cancer. The same study found an increasing statistically significant increase in advanced prostate cancer cases with increasing levels of zinc supplementation. However, at a dosage of less than 25 mg of zinc/day (from supplements), the risk of advanced prostate cancer was decreased 19%, and the risk of prostate cancer in general was decreased 6%.
A study of cancer mortality published in Annals of Epidemiology (Wu 2004), found a statistically significant decrease in overall cancer mortality by 36% with moderate blood levels of zinc, but increased risk at lower and higher levels of zinc. This is a classic U-shaped risk curve: the risk of cancer is higher at both ends of zinc levels. Too little zinc or too much zinc each increases the risk of cancer. But a moderate intake of zinc decreases cancer risk.
So you don’t want a zinc supplement that has the highest amount of zinc per day. Moderation is best with vitamin and mineral supplements. My own choice is a 22 mg/day zinc supplement. I consider that this supplement decreases my risk of infection and also cancer, but also avoids the problems associated with excess zinc.
In future posts, I’ll be reviewing other good choices for supplements to store with your food supplies. Stored food is necessarily limited in its vitamin and mineral content. So supplements are a useful addition to your preps.