The microminerals are 17 essential nutrients that your body needs in relatively small amounts to function effectively. Failing to stick to the recommended daily allowance (RDA) for any of the microminerals can have a number of unpleasant side effects. Today I am going to help you avoid any potential negative side effects and discuss how much of each micromineral you should consume.
1) ARSENIC
RDA:- There is currently no official RDA for arsenic but most sources suggest an intake of between 0.125 milligrams (mg) and 0.025mg per day is adequate.
Tolerable Upper Limit (TUL):- There is currently no official TUL for arsenic. Organic arsenic (which is the natural form found in foods) is not toxic even when high levels are consumed. Inorganic arsenic (which is the unnatural form found in certain chemicals that can in rare instances leak into the soil and water supplies) is toxic at levels of 1mg per day and over.
Deficiency Symptoms:- Failing to consume the RDA for arsenic can lead to abnormal growth, heart disorders and skeletal disorders.
Overdose Symptoms:- Arsenic overdose is very serious but also very rare. Consuming high levels of organic arsenic has no associated overdose symptoms. Overdosing on inorganic acid is much more unpleasant but only happens in the rare instances where drinking water and soil become contaminated. If you do consume too much inorganic arsenic it can lead to anemia (a low red blood cell count), arsenism (a condition where the skin pigmentation changes and layers of horny skin start to develop), cancer (particularly bladder cancer, lung cancer and skin cancer), death, depression, dermatosis (a skin condition which causes eruptions and lesions), gastrointestinal problems, liver damage and peripheral neuropathy (loss of nerve function in the arms and/or legs).
2) BORON
RDA:- There is currently no official RDA for boron but most sources suggest an intake of 1mg per day is adequate.
TUL:- Consuming more than 10mg of boron each day is considered as an overdose. However, toxicity symptoms do not start to develop until daily consumption of this nutrient reaches 50mg and above.
Deficiency Symptoms:- Failing to consume enough boron can lead to numerous negative symptoms. These include arthritis (inflammation of the joints), depression, hormone imbalances, joint problems, kidney stones, mineral deficiency (not eating enough boron reduces the ability of your body to absorb and retain calcium, magnesium, phosphorus and vitamin D), muscle pain, osteoporosis (reduced bone mineral density), reduced bone strength, reduced mental alertness and tooth decay.
Overdose Symptoms:- Eating 50mg or more of boron each day can lead to dermatitis (inflammation of the skin), diarrhea, lethargy, nausea, poor appetite, poor blood circulation, vomiting and weakness.
3) COBALT
RDA:- There is no official RDA for cobalt because it is part of vitamin B12. Consuming the recommended 0.0015mg per day of vitamin B12 will provide your body with adequate amounts of cobalt.
TUL:- Consuming more than 1.4mg of cobalt per day is thought to be toxic.
Deficiency Symptoms:- Cobalt deficiency is very rare as it is found in almost every animal product. However, vegetarians with a limited diet and people with stomach problems that cause a lack of intrinsic factor (a substance which needs to be present in the intestine to properly absorb cobalt and vitamin B12) are at risk. The symptoms of cobalt deficiency include dementia, depression, diarrhea, fatigue, heart disease, menstrual problems in women, nerve damage, pernicious anemia (a condition where your body produces fewer, larger blood cells) and weakness.
Overdose Symptoms:- Most foods contain much less than the TUL for cobalt which means overdosing on this nutrient is extremely rare. However, in situations where an overdose does occur it can lead to decreased fertility in men, heart damage, nausea, thyroid gland damage, vision problems and vomiting.
4) COPPER
RDA:- The RDA for copper increases with age. The list below provides a full breakdown:
– Children aged 0-6 months = 0.2mg.
– Children aged 7-12 months = 0.22mg.
– Children aged 1-3 years = 0.34mg.
– Children aged 4-8 years = 0.44mg.
– Children aged 9-13 years = 0.7mg.
– Children aged 14-18 years = 0.89mg.
– Adults aged 19 years and over = 0.9mg.
– Pregnant women = 1mg.
– Lactating women = 1.3mg.
TUL:- The TUL for copper increases with age. This list below provides a full breakdown:
– Children aged 1-8 years = 1mg.
– Children aged 9-13 years = 5mg.
– Children aged 14-18 years = 8mg.
– Adults aged 19 years and over = 10mg.
Deficiency Symptoms:- Copper deficiency is normally the result of a low dietary intake. However, gastric bypass surgery and consuming high levels of zinc can also reduce the level of copper in the body. Having low levels of copper in the body can lead to anemia, brain disturbances, breathing difficulties, increased low density lipoprotein (LDL) cholesterol levels and reduced high density lipoprotein (HDL) cholesterol levels (which can increase your heart disease risk), iron deficiency, joint problems, poor immune function, ruptured blood vessels, skin sores and weakness.
Overdose Symptoms:- Copper overdose is normally caused by a high dietary intake but it can also be caused by Wilson’s disease (a genetic disorder which causes copper to accumulate in the body). If copper levels in the body do become too high it can cause abdominal pain, depression, diarrhea, dizziness, fatigue, headaches, heart problems, high blood pressure, increased premenstrual syndrome (PMS) symptoms, insomnia, jaundice (a condition where the skin becomes yellow), liver damage, muscle and joint pain, vomiting and weakness.
5) CHROMIUM
RDA:- The RDA for chromium increases with age and is detailed in the table below:
| MEN | WOMEN | LACTATING WOMEN | PREGNANT WOMEN | |
| 0-6 months | 0.0002mg | 0.0002mg | N/A | N/A |
| 7-12 months | 0.0055mg | 0.0055mg | N/A | N/A |
| 1-3 years | 0.011mg | 0.011mg | N/A | N/A |
| 4-8 years | 0.015mg | 0.015mg | N/A | N/A |
| 9-13 years | 0.025mg | 0.021mg | N/A | N/A |
| 14-18 years | 0.035mg | 0.024mg | 0.044mg | 0.029mg |
| 19-50 years | 0.035mg | 0.025mg | 0.045mg | 0.03mg |
| 51 years and over | 0.03mg | 0.02mg | N/A | N/A |
TUL:- There is currently no official TUL for chromium.
Deficiency Symptoms:- Failing to stick to the chromium RDAs listed above can lead to a number of unpleasant symptoms which include high blood glucose levels, high blood pressure, high triglyceride levels (which can indicate poor heart health), hyperinsulinemia (high blood levels of insulin), increased LDL cholesterol levels (a type of cholesterol that clogs your artery walls and can lead to heart disease), insulin resistance (a condition where your body’s cells become less receptive to insulin) and reduced HDL cholesterol levels (a type of cholesterol that removes LDL cholesterol from the body).
Overdose Symptoms:- There are currently no reported chromium overdose symptoms.
6) GERMANIUM
RDA:- There is currently no official RDA for germanium but most sources suggest an intake of 1mg per day is adequate.
TUL:- There is no TUL for natural germanium but consuming 50mg per day or more of certain types of synthetic germanium can cause an overdose.
Deficiency Symptoms:- Failing to eat enough germanium is rare and a deficiency often only develops in individuals with an extremely limited diet. The symptoms of germanium deficiency include cancer, heart disease, immune system disorders, increased LDL cholesterol levels, infection and osteoporosis.
Overdose Symptoms:- Germanium overdose has only been observed in people who consume extremely high levels of certain germanium supplements. In the rare instances where an overdose does occur it can lead to bruising, kidney failure, liver damage and skin rashes.
7) IODINE
RDA:- The RDA for iodine increases with age. The list below provides a full breakdown:
– Children aged 0-6 months = 0.11mg.
– Children aged 7-12 months = 0.13mg.
– Children aged 1-8 years = 0.09mg.
– Children aged 9-13 years = 0.12mg.
– Adults aged 14 years and over = 0.15mg.
– Pregnant women aged 14 years and over = 0.22mg.
– Lactating women aged 14 years and over = 0.29mg.
TUL:- The TUL for iodine fluctuates with age. The list below provides a full breakdown:
– Children aged 1-3 years = 0.9mg.
– Children aged 4-8 years = 0.3mg.
– Children aged 9-13 years = 0.6mg.
– Children aged 14-18 years = 0.9mg.
– Adults aged 19 years and older = 1.1mg.
– Pregnant and lactating women aged 14-18 years = 0.9mg.
– Pregnant and lactating women aged 19 years and older = 1.1mg.
Deficiency Symptoms:- Iodine deficiencies are extremely rare in the UK because most foods contain this nutrient. In the rare instances where a deficiency develops it can lead to appetite fluctuations, depression, fatigue, goiter (enlargement of the thyroid gland), hyperthyroidism (a condition where the body over produces thyroid hormones), hypothyroidism (a condition where the body under produces thyroid hormones), a rapid heartbeat, severe mental retardation and stunted physical growth in infants, weakness and weight gain.
Overdose Symptoms:- It is almost impossible to consume too much iodine from natural food alone. However, excessive consumption of iodine supplements can cause an overdose for which the symptoms include burning in the mouth or throat, diarrhea, nausea, reduced thyroid hormone synthesis (which can cause goiter and hypothyroidism), stomach pain, vomiting and a weak pulse.
8) IRON
RDA:- Women generally need to consume more iron than men as they lose large amounts of this nutrient during menstruation. However, women taking oral contraceptives (which reduce blood loss during menstruation) need to consume slightly less iron. Vegetarians are also advised to consume more iron than non-vegetarians. The table below provides a full breakdown:
| MEN | WOMEN | WOMEN TAKING ORAL CONTRACEPTIVES | LACTATING WOMEN | PREGNANT WOMEN | VEGETARIANS | |
| 0-6 months | 0.27mg | 0.27mg | N/A | N/A | N/A | 26mg |
| 7-12 months | 11mg | 11mg | N/A | N/A | N/A | 26mg |
| 1-3 years | 7mg | 7mg | N/A | N/A | N/A | 26mg |
| 4-8 years | 10mg | 10mg | N/A | N/A | N/A | 26mg |
| 9-13 years | 8mg | 8mg | 11.4mg | 10mg | 27mg | 26mg |
| 14-18 years | 11mg | 15mg | 10.9mg | 9mg | 27mg | 26mg |
| 19-50 years | 8mg | 18mg | 8mg | N/A | N/A | 26mg |
| 51 years and over | 8mg | 8mg | 8mg | N/A | N/A | 26mg for men/33mg for women |
TUL:- The TUL for iron increases with age. The list below provides a full breakdown:
– Children aged 1-13 years = 40mg.
– Adults aged 14 years and older = 45mg.
Deficiency Symptoms:- Iron deficiency is one of the most prominent nutrient deficiencies in the world. It can be caused by consuming high levels of caffeine, oxalates (which are found in certain vegetables), phosphates (which are found in carbonated drinks and processed foods), phytates (which are found in certain nuts and pulses) and tannins (which are found in tea). Donating blood regularly, excessive menstrual bleeding, infection, medical conditions that cause internal bleeding, nutrient deficiency (not getting enough copper, vitamin A or vitamin C can inhibit the absorption of iron) and a poor dietary intake of iron can also contribute to a deficiency.
The symptoms of iron deficiency include depression, dizziness, fatigue, hair loss, headaches, hypochromic anemia (a condition where the red blood cells become paler than normal due to a reduction in haemoglobin which causes the skin to look pale), increased risk of infection, loss of stamina, microcytic anemia (a condition where the red blood cells become smaller than normal), reduced concentration and weakness.
Overdose Symptoms:- Overdosing on iron through natural foods is uncommon. An overdose is normally the result of excessive supplement consumption, regular blood transfusions and hemochromatosis (a metabolic disorder which causes iron to be deposited in the body’s tissues). The symptoms of iron overdose include bronze or grey coloured skin, damage to the intestinal tract lining, dizziness, fatigue, headaches, liver failure, loss of appetite, nausea, shortness of breath, vomiting and weight loss.
9) LITHIUM
RDA:- There is currently no official RDA for lithium although a minimum intake of 1mg per day has been established. Most sources suggest an intake of between 2mg and 3mg per day is adequate.
TUL:- Consuming 100mg or more of lithium each day can lead to overdose symptoms whilst consuming 5 grams (g) or more can be fatal.
Deficiency Symptoms:- Lithium deficiencies are very rare because only small amounts are required by the body. In the rare instances where a deficiency does develop it can cause depression, joint pain, nervous disorders, manic depressive disorders and mania (elevated mood at all times).
Overdose Symptoms:- Most foods only contain trace amounts of lithium so overdosing from natural sources alone is very difficult. However, excessive supplement consumption can cause an overdose for which the symptoms include confusion, diarrhea, dizziness, drowsiness, headaches, high blood pressure, kidney failure, lethargy, muscular weakness and restlessness.
10) MANGANESE
RDA:- The RDA for manganese increases with age and is detailed in the table below:
| MEN | WOMEN | |
| 0-6 months | 0.0003mg | 0.0003mg |
| 7-12 months | 0.6mg | 0.6mg |
| 1-3 years | 1.2mg | 1.2mg |
| 4-8 years | 1.5mg | 1.5mg |
| 9-13 years | 1.9mg | 1.6mg |
| 14-18 years | 2.2mg | 1.6mg |
| 19 years and over | 2.3mg | 1.8mg for non-pregnant women/2.2mg for pregnant or lactating women |
TUL:- The TUL for manganese increases with age. The list below provides a full breakdown:
– Children aged 1-3 years = 2mg.
– Children aged 4-8 years = 3mg.
– Children aged 9-13 years = 6mg.
– Children aged 14-18 years = 9mg.
– Adults aged 19 years and older = 11mg.
Deficiency Symptoms:- Manganese deficiency is extremely rare and has only been observed when this nutrient is deliberately eliminated from the diet. Even when this does happen the body can normally use magnesium as a substitute. However, on the rare occasions where a manganese deficiency does develop it can cause blindness, bone loss, dizziness, extremely low blood cholesterol levels, loss of hearing, high blood glucose levels, loss of hair colour, nausea, paralysis, skin rashes and vomiting.
Overdose Symptoms:- Consuming too much manganese from natural foods is extremely rare. The most common cause of manganese overdose is inhalation of manganese dust but chronic liver disease can also cause a build up of this nutrient in the body. If too much manganese does build up in the body it can lead to interference with copper, iron and zinc, impotency, manganese madness (a syndrome characterised by hallucinations, irritability and violence) and nervous system problems (similar to those experienced by sufferers of Parkinson’s disease).
11) MOLYBDENUM
RDA:- The RDA for molybdenum increases with age. The list below provides a full breakdown:
– Children aged 0-6 months = 0.002mg.
– Children aged 7-12 months = 0.003mg.
– Children aged 1-3 years = 0.017mg.
– Children aged 4-8 years = 0.022mg.
– Children aged 9-13 years = 0.034mg.
– Children aged 14-18 years = 0.043mg.
– Adults aged 19 years and over = 0.045mg.
TUL:- The TUL for molybdenum increases with age. The list below provides a full breakdown:
– Children aged 1-3 years = 0.3mg.
– Children aged 4-8 years = 0.6mg.
– Children aged 9-13 years = 1.1mg.
– Children aged 14-18 years = 1.7mg.
– Adults aged 19 years and over = 2mg.
Deficiency Symptoms:- Molybdenum deficiency is so rare that it has only been observed in people who are fed intravenously or who have the genetic disorder disorder molybdenum co-factor deficiency (which stops people from properly absorbing this nutrient). The symptoms of molybdenum deficiency include anemia, dental cavities, dizziness, headaches, impaired sexual function, night blindness, mental disturbances, nausea, rapid heartbeat and vomiting.
Overdose Symptoms:- Excessive supplement consumption is the most common cause of molybdenum overdose. The overdose symptoms include anemia, diarrhea, gout like symptoms (when daily dosages of above 10mg per day are consumed), high blood levels of uric acid, reduced copper absorption, slow growth, swelling in the joints and weight loss.
12) NICKEL
RDA:- There is currently no official RDA for nickel but most sources suggest an intake of 0.1mg per day is adequate.
TUL:- Consuming more than 100mg of nickel per day can lead to overdose symptoms.
Deficiency Symptoms:- There are currently no reported nickel deficiency symptoms.
Overdose Symptoms:- Most foods only contain small amounts of nickel so an overdose is extremely rare. However, inhalation of nickel fumes can cause toxic levels of this nutrient to enter the body. People who are allergic to nickel (approximately10% of the UK population) may also experience overdose symptoms even when exposed to relatively small amounts. The symptoms of nickel overdose include high blood pressure, increased lung cancer risk, increased susceptibility to infection, reduced bone development, slow growth and skin rashes.
13) SELENIUM
RDA:- The RDA for selenium increases with age. The list below provides a full breakdown:
– Children aged 0-6 months = 0.015mg.
– Children aged 7 months-3 years = 0.02mg.
– Children aged 4-8 years = 0.03mg.
– Children aged 9-13 years = 0.04mg.
– Children and adults aged 14 years and over = 0.055mg.
– Pregnant women = 0.06mg.
– Lactating women = 0.07mg.
TUL:- Consuming more than 0.4mg of selenium per day can cause an overdose.
Deficiency Symptoms:- Selenium deficiencies are rarely caused by poor dietary choices. In most cases a deficiency develops as a result of long term intravenous feeding, low soil concentrations of selenium and serious gastrointestinal problems (which can interfere with the absorption of this nutrient). Being deficient in selenium can lead to an increased cancer risk, Kashin-Beck disease (a bone and joint disorder caused by selenium deficiency), Keshan disease (a heart disorder caused by selenium deficiency), myxedematous endemic cretinism (a disease that causes mental retardation), osteoarthritis (the chronic breakdown of cartilage in the joints), skin inflammation and a weak immune system.
Overdose Symptoms:- Selenium overdose is normally caused by excessive supplement consumption. The symptoms of excessive supplement consumption include bad breath, fatigue, gastrointestinal problems, hair, nail and tooth loss, increased dental cavities, irritability, loss of feeling in the fingers and toes, mild nerve damage and white blotchy nails.
14) SILICON
RDA:- There is currently no official RDA for silicon but most sources suggest an intake of between 1g and 2g is adequate.
TUL:- There is currently no official TUL for silicon.
Deficiency Symptoms:- Silicon can be found in almost every plant based food and only an extremely limited diet can cause a deficiency. In the rare instances where a deficiency does develop it can lead to ageing of the skin, brittle nails, increased sensitivity to cold temperatures, poor bone development, thinning hair and wrinkles.
Overdose Symptoms:- There are currently no reported silicon overdose symptoms. However, long term inhalation of silicon dust can lead to silicosis (a dangerous lung disease).
15) TIN
RDA:- There is currently no official RDA for tin but most sources suggest an intake of between 1mg and 3mg is adequate.
TUL:- Consuming more than 13mg of tin per day can cause an overdose.
Deficiency Symptoms:- Failing to consume at least 1mg of tin per day can lead to asthma, depression, hair loss, headaches, insomnia, left sided heart problems and low adrenals (a condition where the adrenal gland fails to produce adequate hormones).
Overdose Symptoms:- Exceeding the TUL for tin can lead to a number of negative symptoms such as destruction of red blood cells, diarrhea, headaches, nausea, skin rashes, stomach pain and vomiting.
16) VANADIUM
RDA:- There is currently no official RDA for vanadium but most sources suggest an intake of between 0.1mg and 1mg per day is adequate.
TUL:- Consuming more than 1.8mg of vanadium per day can lead to an overdose.
Deficiency Symptoms:- Failing to consume at least 0.1mg of vanadium each day can lead to hyperglycaemia (extremely high blood glucose levels), an increased cancer risk, an increased heart disease risk and increased LDL cholesterol levels.
Overdose Symptoms:- Overdosing on vanadium from natural foods alone is very difficult. However, excessive use of supplements can lead to a vanadium overdose for which the symptoms include anemia, blood vessel damage, dehydration, diarrhea, green tongue, kidney failure, liver damage, lung irritation, nausea, nerve damage, poor appetite, skin irritation, stomach problems, stunted growth, vomiting, a weak immune system (due to a low white blood cell count) and weight loss.
17) ZINC
RDA:- The RDA for zinc increases with age and is detailed in the table below:
| MEN | WOMEN | LACTATING WOMEN | PREGNANT WOMEN | |
| 0-6 months | 2mg | 2mg | N/A | N/A |
| 7-36 months | 3mg | 3mg | N/A | N/A |
| 4-8 years | 5mg | 5mg | N/A | N/A |
| 9-13 years | 8mg | 8mg | 13mg | 12mg |
| 14-18 years | 11mg | 9mg | 13mg | 12mg |
| 19 years and over | 11mg | 9mg | 12mg | 11mg |
TUL:- Consuming more than 40mg of zinc per day can cause an overdose.
Deficiency Symptoms:- Failing to eat enough zinc is the most common cause of deficiency but bowel problems, chronic diarrhea, excessive sweating and consumption of certain medications can also reduce zinc levels in the body. If zinc levels do become too low it can lead to depression, diarrhea, hair loss, impaired growth and mental development in children, impaired taste and smell, increased susceptibility to infection, poor appetite, slow healing of wounds and a weak immune system.
Overdose Symptoms:- It is very difficult to exceed the TUL for zinc from natural foods alone. However, excessive consumption of zinc supplements can cause an overdose. The symptoms of overdose include anemia, a bitter or metallic taste in the mouth, cramps, diarrhea mixed with blood, reduced absorption of copper, magnesium and iron, nausea, stomach pain and vomiting.
SUMMARY
Consuming the correct amounts of microminerals is essential for good health. Getting too little or too much can do serious damage to your body. If you stick to a healthy, balanced diet that contains a variety of natural, unprocessed foods you should hit all the RDAs listed in this article. However, if you are struggling for ideas then check out my list of 10 fantastic micromineral foods for some inspiration.