Thread by @dr_ericberg

Here are 10 vitamins and minerals you should never take, and why:

1/ Magnesium oxide… 🧵

Magnesium is an essential mineral, but not all forms work.

Magnesium oxide is cheap. Your body absorbs only 3 percent, & it can cause diarrhea, flushing out electrolytes.

Choose magnesium glycinate for:
• 80–85% absorption
• Better sleep
• More energy
• Less muscle tension

2/ Synthetic vitamin A

Synthetic vitamin A must convert to its active form, but it does so inefficiently.

It can accumulate in the liver and fat, causing toxicity, bone loss, & birth defects during pregnancy.

Instead, get vitamin A from:
• Egg yolks
• Liver
• Cod liver oil

3/ Synthetic beta-carotene

Not all beta-carotene has protective effects. Synthetic beta-carotene, often made from petroleum, has been linked to higher lung cancer risk in smokers.

Natural beta-carotene from carrots and leafy greens is safe and protective.

4/ Folic acid (vitamin B9)

Folic acid must convert to folate, its active form.

30–40% of people have a gene variant called MTHFR that blocks the conversion.

This acid can build up, raising cancer risk & weakening immunity.
Choose natural folate from dark leafy greens instead.

5/ Synthetic B12 (cyanocobalamin)

“Cyano” refers to cyanide. This form contains trace cyanide & is less bioavailable than natural methylcobalamin.

It can deplete glutathione, a key antioxidant, & may be toxic if your detox pathways are weak.

Get B12 from:
• Red meat
• Liver

6/ Calcium carbonate

Calcium carbonate is poorly absorbed and can accumulate in arteries and kidneys, increasing the risk of heart attacks.

Calcium works best when balanced with magnesium in a 1:1 ratio.

Get calcium naturally from:
• Cheese
• Yogurt
• Kefir
• Leafy greens

7/ Iron (ferrous sulfate)

Iron is corrosive and hard to excrete.

Excess iron raises risks for:
• Type 2 diabetes
• Liver issues
• Parkinson’s and Alzheimer’s

Get iron naturally from liver or red meat. Avoid supplements unless specifically recommended.

8/ Synthetic vitamin D (ergocalciferol)

This form is made by irradiating fungus or yeast.

Its conversion to active vitamin D is inefficient, and it binds weakly to transport proteins.

Natural vitamin D3 from sunlight or cod liver oil is far more effective.

9/ Omega-6 seed oils

Some supplements include linoleic acid, an omega-6 fat.

The average diet contains about 25 times more omega-6 fats than omega-3 fats.

Excess omega-6 promotes inflammation.

Better sources of healthy fats include:
• Fish
• Cod liver oil
• Grass-fed meat

10/ Copper

Copper is essential in trace amounts.

But too much, especially without proper zinc balance, can contribute to brain and liver toxicity, oxidative stress, and increased Alzheimer’s risk.

Get copper naturally from:
• Shellfish
• Liver
• Dark chocolate

Many cheap synthetic vitamins are not just ineffective. They can be dangerous.

Focus on nutrients from real foods like eggs, liver, leafy greens, fish, and whole foods.

Watch this video to learn more:

A bit about me:

I’m the creator of Healthy Keto® and Intermittent Fasting protocols, helping over 100M people make healthier choices.

Follow me @dr_ericberg for more evidence-based insights to improve your health and longevity.

Most people waste months trying to fix everything at once, when only 1 thing actually needs fixing first. Fix that, and everything else starts to fall into place.

Take my free 2-minute quiz to find the #1 fix specific to you: drbrg.co/4vOtgMG

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Dr. Eric Berg, DC, not MD; information only.