Supplements: Good or Bad
For the most part unless you have a true dietary deficiency, supplements are a waste of money and or cause damage. I will give a few examples below. Also you need to know that when studies show that some vitamin , mineral , etc are shown to prevent or help certain conditions it is when they look at population studies where people eat foods high in that particular vitamin, etc. It is important to note that how a vitamin is presented to our body is important, so as food not a lone chemical. Also in the individual supplement market they typically give a much higher dose than we would get from eating food rich in it. Too much of anything can cause harm. Example: you will die if you drink too much water.
Supplements
Vitamins - 11 of 13 are made by plants
Vitamin D is a hormone made by our skin when exposed to sun Vitamin B-12 is made by soil bacteria
Minerals come from the soil and are absorbed by plants through their roots
Examples of Where Supplements can be bad
B- carotene - people who ate a diet high in this had a 28 % decrease in risk of lung cancer
So gave supplement and died sooner- why ? In this case they suspect that it is related to the other 50 carotenoid receptors in the body that were saturated by the excess supplements . This then prevented the other carotenoids from being able to bind to them and created an imbalance.
Vitamin E a known antioxidant was used for awhile by cardiologists to help with heart disease. Then they found that this led to more frequent and earlier deaths.
JAMA May 12 , 2010 - Elderly white females given large doses of Vitamin D had 26 % more fractures then placebo group
Only supplement that McDougall recommends is Vitamin B-12. Only need 5 ug/day . So one 200 ug capsule once every week or couple of weeks would be fine.