Nutritional Deficiencies

Micronutrient & Recommended Daily Allowance (RDA)

Complications arising from deficiency

• Required for the synthesis of thyroid hormones which are involved primarily in regulating heart rate, the rate of digestion, weight, and energy levels

• Vital for foetal development

• Abundant in iodised salt,  seafood (85g of baked cod provide 66% of the DV), seaweed (1g of kelp packs 460–1,000% of the DV) 

• Goitre, which is the enlargement of the thyroid gland, usually manifesting as a swelling in the neck, rapid heart rate, shortness of breath, difficulty swallowing etc. 
• Congenital iodine deficiency syndrome causes cretinism (physical deformities – short stature, bone deformities, and intellectual disabilities.)

Adults: 150mcg/day

Pregnant women: 220mcg/day

• Helps absorb calcium and phosphorous from food; also regulates calcium homeostasis in the kidney. This affects bone health, blood pressure, cardiovascular health, and neurodevelopment
• Involved in immune function
• Helps to regulate cell growth and differentiation 

• Dietary sources e.g. egg yolk (One large egg yolk contains 7% of the DV), fatty fish like mackerel, salmon (A small 85g serving of cooked salmon provides 75% of the DV), red meat, fortified milk or breakfast cereals
• Synthesized with sun exposure – 5 to 30 minutes of midday sun exposure twice a week on the face, arms, neck, or back can provide you with enough vitamin D.

• Weak/brittle bones lead to rickets in children, predisposes to osteoporosis and fractures 
• Dysregulation of calcium homeostasis can lead to heart disease, stroke

Adults: 15mcg (600IU)/day

>70yo: 20mcg (800IU)/day

• Involved in the production of certain cells e.g. B- and T-cells, which play central roles in immune responses against disease.
• Maintaining good vision
• Essential for reproduction – plays a role in sperm and egg development.
• Also critical for placental health, foetal growth.

• Foods of animal origin – cod liver oil (one tablespoon contains ~500% of the DV), liver (one 60g slice of beef liver contains ~800% of the DV)

• Beta-Carotenes (converted into Vitamin A):  carrots (one large carrot provides 75% of the DV), sweet potato (one medium 170g boiled sweet potato contains 150% of the DV), spinach (one 28g serving of fresh spinach provides 18% of the DV)

• Increased susceptibility to infection 
• Eye (ocular) problems such as blindness in children, night blindness in pregnant women and corneal ulceration
• Pregnancy complications

Men: 900 mcg/day

Women: 700 mcg/day

• Required to form healthy red blood cells
• For foetal development – brain and nervous system functioning

• • Beans (one 177g cup of cooked kidney beans contains 33% of the DV) and lentils 
  • Dark leafy greens e.g. kale, spinach (One 30g serving of raw spinach provides 15% of the DV)
• Fortified grains (One 140g cup of cooked spaghetti contains ~26% of the DV)

• • Meat (poultry, pork)
• Folic acid tablets

• Folate deficiency anaemia; symptoms include extreme tiredness, weakness
• Foetal abnormality – neural tube defect (such as spina bifida)

Adults: 400mcg/day

Pregnant women: 400-1000mcg/day

• Necessary to produce red blood cells, which carry oxygen throughout the body,

• Organ meat (One 81g slice of liver gives >50% of the DV)
• Shellfish e.g. Clams, mussels, and oysters (85g of cooked oysters provide ~50% of the DV.)
• Canned sardines (One 106g can offers 34% of the DV.)
• Beans (Half a cup or 85g of cooked kidney beans provides 33% of the DV.)
• Seeds e.g. pumpkin, sesame, and squash seeds (One 28g serving of roasted pumpkin or squash seeds contains 11% of the DV)
• Dark, leafy greens e.g. Broccoli, spinach, kale (One 28g serving of fresh kale provides 5.5% of the DV)

• Iron deficiency anemia i.e. decrease in red blood cells and blood’s ability to carry oxygen; symptoms usually include tiredness, weakness, shortness of breath, a weakened immune system, and impaired brain function

Adult >50yo: 8 mg/day

Adult women <50yo: 18 mg/day

• Maintain strong bones and teeth
• Control muscle and nerve function
• Maintain heart function

• Dairy products – cheese, milk, yoghurt (3 servings a day will meet RDA)
• Fortified cereal or orange juice

• Dark leafy greens e.g. spinach, kale (one 28g serving of fresh kale offers 5.6% of the DV)

• Weak, brittle bones
• Numb, tingling fingers
• Abnormal heart rhythm

Adults:1000mg/day

♀ > 50yo and
♂ > 70yo: 1200mg/day

• Helps support bone health
• Involved in >300 biochemical reactions in the body 
• Maintain normal nerve and muscle function
• Keeps the heartbeat steady
• Assists in energy production

• Whole grains (One 170g serving of oats contains 74% of the DV)
• Nuts (20 almonds pack 17% of the DV)
• Dark chocolate (One 30g serving of dark chocolate offers 15% of the DV)
• Dark green, leafy vegetables (One 30g serving of raw spinach provides 6% of the DV)

• Loss of appetite, nausea and vomiting, fatigue, and weakness
• In severe cases, it may lead to numbness and tingling, muscle cramps or contractions, seizures, irregular heart rhythms etc. 

Adults: 1000mg/day

♀ 320mg/day
♂ 420mg/day

Pregnant women: 360mg/day

• Involved in the production of red blood cells and DNA, 
• Ensures proper functioning of the nervous system

• Shellfish e.g. Clams and oysters (One 85g portion of cooked clams provides 1400% of the DV)
• Organ meat (one 60g slice of liver packs >1000% of the DV)
• Meat (A small, 170g beef steak offers 150% the DV)
• Eggs (one egg provides ~6% of the DV)
• Milk products (one 240 ml cup of whole milk contains about 18% of the DV)

• Megaloblastic anemia i.e. red blood cells produced in the bone marrow are too large to pass out of the bone marrow into your circulation; symptoms include pale, jaundiced skin, weakness and fatigue, breathlessness, dizziness
• ↑ homocysteine levels, predisposes to arterial damage and blood clotting, thus also ↑ risk of stroke, coronary artery disease, dementia
• Depressed mood

Adults <50yo: 2.4mcg/day#

Pregnant women: 2.6mcg/day

#Elderly need more; with age, the body makes less stomach acid and intrinsic factor (a type of protein)— both of which can affect the absorption of vitamin B12.