Too much vitamin B6 can lead to nerve damage, skin lesions, and increased risk of hip fracture.

Too little can cause dermatitis, pins and needles in extremities, sore or cracked tongue, and confusion.

RDA: 1.3 mg for adults under 50, 1.5 mg for women older than 50, and 1.7 mg for men over 50

Foods rich in Vitamin B6 are: beef liver, tuna and salmon, poultry, fortified cereals, chickpeas

Too little vitamin B12 can cause constipation, diarrhea, loss of appetite, gas, nerve problems like numbness and tingling, muscle weakness, walking problems, vision loss, etc.

Too much can cause a headache, but the body only absorbs what is needed and rest is passed in urine

RDA: 2.4 mcg for adults

Foods rich in vitamin B12 include: meat, fish, milk, cheese, eggs

Too little biotin can lead to skin rash, hair loss, brittle nails, high blood levels of cholesterol, and heart problems.

Too much can result in insomnia, excessive thirst, and urination.

There is no RDA, but most healthy people get enough biotin from their normal diet. Biotin amounts can be addressed using AI, indicating there is an adequate intake. Excess is excreted in the urine.  

Biotin rich foods include: egg yolk, organ meat, nuts, white mushrooms, wheat germ

Too much vitamin C can cause nausea, vomiting and diarrhea, heartburn, stomach cramps and bloating.

Too little can lead to scurvy, in which symptoms include fatigue, inflammation of gums, small red or purple spots on skin, joint pain, poor wound healing, corkscrew hairs, and easy bruising and bleeding.

RDA: 90 mg for men and 75 mg for women over the age of 19

Foods rich in vitamin C include: citrus, bell pepper, strawberries

Too much calcium is called hypercalcemia, in which the body experiences weakened bones, the creation of kidney stones, and interference with heart and brain function (hypercalcemia can happen from overactive parathyroid glands).

Too little can result in low bone mass, osteoporosis, numbness and tingling in fingers, convulsion and abnormal heart rhythm, and fatigue.

RDA: 1000 mg daily for women ages 18-50 and men of all ages, 1200 for women over 50 due to increased risk of osteoporosis. 

Foods rich in calcium are: milk, cheese, yogurt

Too much vitamin E is rare, but can lead to increased risk of bleeding, muscle weakness, fatigue, nausea, and diarrhea.

Too little can result in nerve and muscle damage, loss of feeling in arm and legs, muscle weakness, vision problems, and loss of body movement control.

RDA: 15 mg for adults over the age of 14.

Vitamin E rich foods include: sunflower seeds, peanuts and peanut butter, pumpkin

Too much folate can cause weakness, fatigue, shortness of breath, and difficulty concentrating.

Too little leads to megaloblastic anemia (larger than normal red blood cells that are fewer in number and oval shaped).

RDA: 400mcg for women and men 19 years or older, 600 mcg when pregnant

Food rich in folate are: dark leafy greens like spinach, Brussel sprouts, broccoli; beans, peanuts