This table compares the typical levels of recommended daily nutrient intake to the United States Tolerable Upper Intake Levels ( ULs) and the United Kingdom 's Safe Upper Levels (SULs). The Recommended Dietary Allowance (RDA) and Adequate Intake (AI) values are considered to be levels of nutrient intake that meet or exceed the needs of practically all healthy people. The Daily Value amounts, that are currently used as reference values on food and supplement labels, are similar to the RDA/AI values, but differ in some cases. UL values are the amounts that are considered to be the maximum safe level of intake from food and supplements combined. SUL values are the maximum level of intake of a nutrient from dietary supplements that can be considered to be reasonably safe.

How much is too much?

Comparison of Dietary Reference Intake Values (for adult men and women) and Daily Values for Micronutrients with the Tolerable Upper Intake Levels (UL),a,c Safe Upper Levels (SUL),d and Guidance Levelsd

 

Nutrient	RDA/AIb (men / women) ages 31-50	Daily Value (Food Labels)	ULc	SUL or Guidance Leveld	Selected Potential Effects of Excess Intake
Vitamin A (mcg)	900 / 700	1500 (5000 IU)	3000	1500** (5000 IU)	Liver damage, bone & joint pain, dry skin, loss of hair, headache, vomiting
beta-Carotene (mg)	-	-	-	7 (11,655 IU)	Increased risk of lung cancer in smokers and those heavily exposed to asbestos
Vitamin D (mcg)	15 (600 IU)	10 (400 IU)	100	25 (1000 IU)	Calcification of brain, arteries, increased blood calcium, loss of appetite, nausea
Vitamin E (mg)	15	20 (30 IU)	1000	540 (800 IU)	Deficient blood clotting
Vitamin K (mcg)	120 / 90*	80	-	1000**	Red blood cell damage/anemia; liver damage
Thiamin (B1) (mg)	1.2 / 1.1	1.5	-	100**	Headache, nausea, irritability, insomnia, rapid pulse, weakness (7000+ mg dose)
Riboflavin (B2) (mg)	1.3 / 1.1	1.7	-	40**	Generally considered harmless; yellow discoloration of urine
Niacin (mg)	16 / 14	20	35	500**	Liver damage, flushing, nausea, gastrointestinal problems
Vitamin B6 (mg)	1.3	2	100	10	Neurological problems, numbness and pain in limbs
Vitamin B12 (mcg)	2.4	6		2000**	No reports of toxicity from oral ingestion
Folic acid (mcg)	400	400	1000	1000**	Masks B12 deficiency (which can cause neurological problems)
Pantothenic acid (mg)	5*	10	-	200**	Diarrhea & gastrointestinal disturbance (10,000+ mg/day)
Biotin (mcg)	30*	300	-	900**	No reports of toxicity from oral ingestion
Choline (mcg)	550/425*	-	3500	-	Fishy body odor (trimethylaminuria), hepatotoxicity
Vitamin C (mg)	90 / 75	60	2000	1000**	Nausea, diarrhea, kidney stones
Boron (mg)	-	-	20	9.6	Adverse effects on male and female reproductive system
Calcium (mg)	1000	1000	2500	1500**	Nausea, constipation, kidney stones
Chloride (mg)	2300*	3400	3600		Increased blood pressure in salt-sensitive individuals (when consumed as sodium chloride)
Chromium (mcg)	35/25*	120	-	10,000**	Potential adverse effects on liver and kidneys; picolinate form possibly mutagenic
Cobalt (mg)	-	-	-	1.4**	Cardiotoxic effects; not appropriate in a dietary supplement except as vitamin B-12
Copper (mcg)	900	2000	10000	10000	Gastrointestinal distress, liver damage
Fluoride (mg)	4 / 3*	-	10	-	Bone, kidney, muscle, and nerve damage; supplement with professional guidance
Germanium	-	-	-	zero**	kidney toxin; should not be in a dietary supplement
Iodine (mcg)	150	150	1100	500**	Elevated thyroid hormone concentration
Iron (mg)	8 / 18	18	45	17**	Gastrointestinal distress, increased risk of heart disease, oxidative stress
Magnesium (mg)	420 / 320	400	350e	400**	Diarrhea
Manganese (mg)	2.3 / 1.8*	2	11	4**	Neurotoxicity
Molybdenum (mcg)	45	75	2000	zero**	Gout-like symptome; joint pains; increased uric acid
Nickel (mcg)	-	-	1000	260**	Increased sensitivity of skin reaction to nickel in jewelry
Phosphorus (mg)	700	1000	4000	250**	Alteration of parathyroid hormone levels; reduced bone mineral density
Potassium (mg)	4700*	3500	-	3700**	Gastrointestinal damage
Selenium (mcg)	55	70	400	450	Nausea, diarrhea, fatigue, hair and nail loss
Silicon (mg)	-	-	-	700	Low toxicity; possibility of kidney stones
Sodium (mg)	1500*	2400	2300		Increased blood pressure in salt-sensitive individuals (when consumed as sodium chloride)
Vanadium (mg)	-	-	1.8	zero	Gastrointestinal irritation; fatigue
Zinc (mg)	11 / 8	15	40	25	Impaired immune function, low HDL-cholesterol