Beer : Health and Nutrition

The Basics of Human Nutrition 93
for thiamine if alcohol is present at high levels. It is equally important to stress that
excessive intake of vitamins may have adverse effects. For the most part this pertains
to two of the fat-soluble vitamins, A and D, though B 6 at levels above 50 mg per day or
nicotinic acid in excess of 2–6 g per day are of concern for neurological damage and
liver damage respectively (Finglas 2003).
Minerals
Table 4.3 lists the requirements of the human for minerals and their various impacts.
Minerals comprise only 4–6% of the body (Freeland-Graves & Trotter 2003) and some
of them are needed only in vanishing quantities. Calcium, chloride, magnesium, phosphorus,
potassium and sodium are the major minerals. Chromium, copper, uoride,
iodide, iron, manganese, silicon and zinc are needed in trace quantities. Arsenic, boron,
molybdenum, nickel, selenium and vanadium are ‘ultra trace’ minerals.
Table 4.3 Minerals and their significance.
Mineral Notes
Calcium Needed for teeth and bones (e.g. lack causing osteoporosis in older women) and blood
clotting. By interaction with phosphate these two minerals mutually antagonise one
another’s uptake. Also binding with other components will limit uptake, e.g. oxalate
Phosphorus Needed for teeth and bones and energy metabolism
Magnesium Needed for nerve and muscle function
Iron Component of haemoglobin and myoglobin. Uptake may be limited by complex
formation, e.g. with phytate and phosphate
Copper Component of key oxidative enzymes
Cobalt Part of vitamin B 12
Zinc Needed by several enzymes; implicated in reproduction, growth, skin integrity and
wound healing
Sodium Maintenance of osmotic equilibrium and body uid volume
Chloride Maintenance of osmotic equilibrium and body uid volume. Also needed in manufacture
of stomach hydrochloric acid
Potassium Helps sodium in regulating ionic balance across membranes
Iodine Part of thyroid hormone, de ciency causing goitre
Fluoride Needed for sound teeth and bones
Chromium Glucose metabolism, insulin sensitivity
Manganese Cartilage and bone equity, lipid and carbohydrate metabolism
Silicon Bone calci cation and cartilage formation
Arsenic Taurine and polyamine metabolism
Selenium Antioxidant, thyroid hormone metabolism
Boron Energy utilisation, bone development
Molybdenum Sulphur and nucleic acid metabolism
Nickel Production of hormones
Vanadium Iodine metabolism