Iodine;an overlooked micronutrient

Iodine, one of the most important micronutrient required at all stages of life. Iodine is essential for the synthesis of Thyroid hormone, triidothyronine (T3 )and thyroxine (T4) which regulates body metabolism. Thyroid hormones receptors are presents in almost every cell of the body, so they are important regulators of many physiological processes includes brain development, growth, metabolism and cardiac function. Iodine plays a vital role in brain development during early pregnacy till childhood. Many brain structures and systems appear to be affected with iodine deficiency, including areas such as the hippocampus, microstructures such as myelin, and neurotransmitters.

25 -30mg of iodine present in a healthy body, 80% of which is stored in the thyroid gland. The non hormonal iodine is found in a variety of body tissues including mammary glands, eye, gastric mucosa, cervix and salivary glands.

How much Iodine Do we Need

In the UK, the recommended daily intake of iodine for a healthy adult (male and female) is140 microgram and there is no specific recommendation for pregnant and breastfeeding women. As during pregnancy, iodine requirement increases so the British Dietetic Association (BDA) suggested 200 microgramm of iodine per day for pregnant and breastfeeding women.

dietary sources of iodine

Milk and dairy products fish and eggs are a major source of iodine. In the UK, milk and dairy products provide as much as 34% of iodine intake. Fortified milk is recommended for those who are using non dairy milk alternative. however, a study conducted by the University of surry revealed that only a few plant based milk brands in UK are fortified with iodine.

Fruits and vegetables also contain iodine but the amount varies depending on the iodine content of the soil, fertilizers use up and irrigation practice. The table below produced by BDA shows the iodine content of food in the UK.

Some vegetables impair absorption of iodine like cruciferous vegetables (broccoli, cauliflower, cabbage and soya) and cause swelling of the thyroid gland (goitre) due to low levels of thyroid hormones. However, normal consumption of cruciferous vegetable does not appear to increase the risk of hypothyroidism unless accompanied by iodine deficiency. 

iodine deficiency

  • Pregnant and lactating women; The iodine requirement in pregnant women is 50% higher as compared to non preganant women as; maternal iodine production increases by 50% in eraly pregnancy.At this stage fetal thyroid is not fully active so, additional iodine is rquired for fetus toproduce its own thyroid hormones.
  • vegetarian /vegans
  • People with food allergies; milk or fish allergies
  • Lactose intolerance

Globally, iodine deficiency is a serious public health issue and it is estimated that around 2 billion people all over the world are iodine deficient. iodine deficiency leads to hypothyroidism which causes impair neurodevelopment in early childhood.

It is claimed by WHO that iodine deficiency is the most significant preventable cause of brain damage and mental retardation. Severe iodine deficiency during pregnancy causes Endemic cretenism( congenital hypothyroidism) in the newborn which is marked by gross mental retardation, deaf mutism, short stature.

iodine deficiency causes a spectrum of disorders in different age groups collectively known as iodine deficiency disorders ( DIDs). The effects of IDD in humans at different stages of life are presented in the following pyramid.

Iodine deficiency can be corrected by adding iodine to dietary media like salt, oil, water, sauces etc. The methods of proven value for mass use are iodized salt and iodized oil. To this end, fortification of salt with iodine has been identified and considered to be the most suitable method of fortification.

universal iodized salt is recommended intervention by WHO for iodine deficiency however, in the UK there is no iodized fortification program and most sale salts are not fortified. it is better to meet iodine requirement through diet.

TAKE HOME MESSAGE;

Iodine is essential for thyroid hormone production and its deficiency may impair body metabolism and brain development.

The best way to meet your daily iodine requirement is eating a healthy well balanced diet. People with different dietary choices like vegan and vegetraian are increased risk of developing iodine deficiency.

vegans should check their iodine levels and in case of iodine deficiency, consume iodine supplements but always consult GP, dietitian or nutritionist before using iodine supplements.

Strong evidence is still needed to conclude the efficacy of iodine supplementation in mild to moderate iodine deficient women on the cognitive function of their children.

Avoid seaweed based supplements as they may cause iodine intoxication.

iron; what you need to know

Iron is one of the most important micronutrient required for normal functioning of the body. About 70% of stored iron found in red blood cells and muscles cells. Red blood cells contain a protein called haemoglobin which is composed of four subunits and each subunit contain hemegroup (iron in the centre), oxygen bind to this heme group, while myoglobin in muscles cells stored, transport and release oxygen whenever body needed.

  • oxygen transportation
  • red cell production(erythropoiesis)
  • DNA synthesis
  • metabolism and immune function.

how much do we need;

According to British dietetic association, daily recommendations for iron varies. People have different requirements, acoording to heir age, sex, physiological state like pregnancy, and sometimes their state of health. Routine iron supplementation is not recommended for pregnant women in UK.

infants 0-3 months 1.7mg
4-6 months 4.3 mg
7-12 months 7.8mg
childrens 1-3 years 6.9mg
4-6 years 6.1mg
7-10 years 8.7 mg
Adolescents 11- 18 years 14.8 mg(girls)
11.3 mg(boys)
Adults 19-55 years 14.8 mg(females)
19-55 years 8.7 mg(males)
55+years 8.7mg

dietary sources of iron ;

Iron is found in two forms; heme and non heme. heme is animal derived iron and absorbed rapidly as compared to non heme iron which ismostly derived from plant. Heme iron absorb at the rate of 35% while non heme absorb at the rate of 25% and its absorption affected by several factors in food like ; Phytate (present in fibre containing food), Tannins (present in tea and coffee) and calcium. Certain medicines like H2 receptors blockers (used for the treatment of acidity and stomach ulcers), Cholesterol-lowering medications inhibit the absorption of iron.

Vitamin C reduces the inhibitory effect of phytates, polyphenols, calcium and egg proteins and enhances the absorption of iron.

Spinach; spinach is a rich source of iron, about 3.5 ounces of raw spinach contain 2.7mg of iron

Broccoli; Broccoli is a good source of iron,1 cup of cooked broccoli contains 1 mg of iron. Moreover, it is packed with vitamin C, which helps in iron absorption.

Dates; they are an excellent source of iron, carry 0.90 mg/100 g of fruits.

Dried apricots contain 2.6 milligrams of iron per 100 grams. 

Red meat; 3.5 ounces of ground beef contain 6.5 mg of iron.

Turkey; 3.5 ounces (100gramm) of turkey meat has 1.43 mg of iron.

Legumes; beans lentils chickpeas peas and soybean are all good sources of iron, one cup of cooked lentils contain 6.6mg of iron.

Quinoa; 185 gm of cooked quinoa contains 2.8mg of iron.

Pumpkin seeds; 1 ounce of pumpkin seeds contains 2.5 mg of iron.

iron deficiency;

  • Blood loss; Blood loss is the most common cause of iron deficiency. In men and postmenopauseal women, low iron status is almost results from gastrointestinal bleeding.
  • Increased iron requirement: pregnancy, lactation
  • Diminished iron absorption: celiac disease and atropic gastritis.

signs and symptoms of iron deficiency;

  • Lethargy, fatigue
  • pale coloured skin and lower eyelid
  • clubbing of nails
  • increased sensitivity to cold
  • imapaired concentration
  • poor immune system

Low iron status may result in iron deficiency anaemia, more than 2 billion people all over the world suffering from iron defiecency anaemia, making it the most common nutritional deficiency condition.

iron deficency anaemia in pregnant women increases the risk of prinatal infections, pre eclampsia and bleeding. Mternal anaemia also associated with poor fetal wellbieng and is linked to the low birth weight, prematurity and fetal death.

excess iron intake can be harmful;

Excess iron intake can also harmful. certain epidemiological studies indicate a link between high iron intake and increased incidence of cardio vascular disease, type2 diabetes and some cancer of digestive tracrt.

take-home message;

  • Eat balanced diet consist of all food groups, if you are vegan or vegetarian always eat combination of food so iron absorption is not compromised
  • Do not drink tea or coffee with food as they impair absorption of iron.
  • seek your GP advice if; feel tried, women with heavy periods, people with renal diseases or on medication which impair iron absorption.

Carbohydrates; friend or foe

Carbohydrates one of the important macronutrient found in food along with fats and protein, but the most misunderstood nutrient. People often say carbs as fattening and linked to various diseases, but this is not a real story. Let’s examine their role and bust this myth surrounding this hotly debated topic.

Types of carbohydrates:

Simple carbohydrates; simple carbohydrates consist of molecule called glucose. They rapidly degraded inside the body and raises blood glucose level. examples are honey, maple syrup, fruits and vegetables. Added sugar in cakes,candies and fruit juices is also simple carbs.

Complex carbohydrates; complex carbohydrates are starch and fibre. These are consist of long chain of glucose molecules. Examples are potatos, corn. Refined carbohydrates like white bread and pastries are also strach. Fibre is a plant derived indigestible carbohydrate.

Why we need carbohydrates:

  • Primary source of energy; The main function of carbohydrates is to provide energy. carbs are quicker to process and provide fuel to our body.our brain consume more than 20% of total energy intake and glucose is the main fuel for brain cells.unused glucose is stored in muscles and liver in the form of glycogen.
  • Important for Gut health; Fibre is helpful in digestion and improves our gut health. Our gut is the host of around 1 trillion microorganisms. several studies show that these microorganisms are crucial for various aspects of our health. Dietary fibers are indigestable and feed our gut microbiota and promote growth of GOOD bacteria.
  • Carbohydrates helps preserve muscles mass; carbohydrates prevent the breakdown of protein for energy and preserve muscles mass.
  • They influence heart diseases and Diabetes; carbohydrates enrich with fibre, reduces the risk of heart diseases, diabetes and some form of cancer. One study shows that people eating cereal based fibre have a decreased risk of colon cancer. Oats and barely contain a special chemical called Beta glucan which may helps to reduce blood cholesterol levels.

How much carb do we need

Daily recommended intake for carbohydrates is 45-65% of total caloric intake and 130gm of glucose is needed for adequate supply of energy to the brain.

Why people think carbs are bad for our health;

Carbohydrates have a bad reputation as people think eating carb means they are eating an unhealthy diet and may gain weight, but all carbohydrates are created not equally. What makes a carb good choice for our health. complex carbohydrates are good for our health as they are

  • lower in calories
  • nutrient dense like minerals vitamins and fibre
  • lower in salt and fats

while simple carbohydrates like sugar, processed food, candies, fizzy drinks fruit juices and pastries.They ae not good for our health as they are

  • lower in nutrients
  • higher in calories
  • higher in salt and fat

These carbohydrates are linked to obesity and other chronic dieaeses as reported by studies. These carbs increase blood glucose levels rapidly and to combat this hyperglycemia, our body releases insulin. insulin promotes glucose storage in muscles and liver and allows the entry of glucose into fat cells by converting glucose into fatty acids. long term intake of a diet high in refined carbs may cause insulin resistance and increase the risk of obesity and type 2 diabetes. Moreover, sugary drinks are a leading cause of tooth decay in children and adults.

what’s the answer to carbohydtrates;Eating the right type of carbs with moderation.

  • Look for carbohydrates which makes you fuller for longer with minium calories like wholegrains, fruits and vegetables.
  • Avoid refined or procesed carbohydters.limit the intake of added sugars.
  • Take note of your body; whats makes you happy and energize and what food makes you lethargic and bloated. Notice pattern of your body, adjuct accordingly and choose your carb wisely.

Do not eat less, eat right ”.