1) Take the vitamins with food or at least milk.
2) Make sure you aren’t taking more than the recommended daily amount (RDA).
3) In many people Omega-3 supplements can cause an upset stomach, as can zinc, even at the recommended doses.
If you take too much:
Vitamin B6 is usually safe, at intakes up to 200 mg per day in adults. However, vitamin B6 can cause neurological disorders, such as loss of sensation in legs and imbalance, when taken in high doses (200 mg or more per day) over a long period of time. Vitamin B6 toxicity can damage sensory nerves, leading to numbness in the hands and feet as well as difficulty walking. Symptoms of a pyridoxine overdose may include poor coordination, staggering, numbness, decreased sensation to touch, temperature, and vibration, and tiredness for up to six months. Source
An omega-3 overdose is likely to cause any of the usual omega-3 side effects, but perhaps more severely. In particular, stomach upset can be expected. In serious cases, an overdose could increase the risk of bleeding, including dangerous internal bleeding, such as gastrointestinal bleeding or bleeding in the brain. Symptoms of such bleeding may include:
* Easy bruising or bleeding
* Black, tarry stools; bright red blood in the stool; or vomiting of blood (signs of gastrointestinal bleeding)
* Signs of a hemorrhagic stroke (bleeding in the brain), such as vision or speech changes, weakness or numbness in an arm or leg, or a severe headache. Source
The danger of taking zinc supplements can be summarized in two words: zinc overdose. A zinc dose of 40 milligrams is approved safe to use by FDA and a zinc dosage more than this can pose certain risks. In terms of zinc toxicity, there is no other way to put it: excess zinc is dangerous! This is primarily true because too much zinc will likely interfere with the metabolism and absorption of other essential minerals in your body, most especially iron, magnesium and copper. Zinc side effects can become potentially serious if you take doses from 150 to 450 mg a day. Taking this much can decrease your copper, iron and magnesium levels, reduce your body’s immune function, and reduce your HDL (good cholesterol) level.
Zinc Sulfate Side Effects
Oral zinc sulfate supplements can also cause side effects such as stomach upset, heartburn and nausea. Rare side effects have also been reported and these include fever, sore throat, mouth sores, weakness and fatigue. Zinc is a very important mineral but you only need to take just enough. If you decide on taking mineral supplements for one or more reasons, it is very important that you consult your doctor first and report whatever zinc side effects you experience. Source