Frank Horwill



  • These articles were first published many year's ago and whilst some are as relevant today as they were when new, many are now mostly of historical interest as modern research and coaching methods have superseded them.

How can I detect a vitamin or mineral deficiency

by Frank Horwill

Actually, if one eats moderate-size meals every four hours it’s very rare to get a mineral or vitamin deficiency. This is because some inadequacies only become apparent after several months of none or little consumption. But, there is another problem: modern farming methods, which use massive amounts of artificial fertilisers to get high yields, denude the soil of vital minerals. This means that some foods have little real goodness in them. There is also, a rather difficult thing to detect – biological individuality. For example, the test for vitamin C adequacy is done via a urine test. When twelve athletes were given 1,000mg of it a day for seven days, some revealed traces of it in their urine indicating that it was too much, while others did not reveal signs until they were taking 4,000mg a day! A four-fold variation!

Here is a list of vital vitamins and minerals for maximising performance in endurance runners:-

Iron – No iron, no oxygen, no athlete. Symptoms: White complexion. Pale membranes inside eyelids. Breathlessness for simple tasks, such as walking upstairs. Declining training and racing performance. Insomnia. Pins and needles in the feet. Gastric upsets. While an haemoglobin test will reveal the oxygen-carrying power of blood, it will not reveal the true body’s iron status; this is done with a serum ferritin test which should be not less than 30 nanogrammes (ng/dl) in males, and 25ng/dl in females. An athlete who gets continually injured should suspect a serum ferritin shortage, as the muscles will tire more quickly and give less support to ligaments and tendons. A problem exists for those who rely on vegetables to get their iron. The iron in vegetables is less bio-available than iron in meats. Good sources are:- liver, kidney, heart, egg yolk, legumes, cocoa, cane molasses, shellfish and parsley. Moderate sources include: muscle meats, fish, poultry, nuts, green vegetables and wholemeal bread. When in doubt, take quest synergistic iron, which contains all the vitamins and minerals to make iron readily absorbed.

Vitamin C – Some of this vitamin is stored in the eyes and adrenal glands. The latter produces acth which is a prerequisite for physical activity. Symptoms:- Frequent colds and infections. Easy bruising. If a hair is pulled from the leg, it will immediately coil or become distorted, it will also leave some specks of blood behind around the follicle. Some vitamin C has an affinity for cartilage, chronic knee problems have been treated by naturopaths with 1,000mg of vitamin C every hour for a day, reducing to once every two hours on the second day, and every three hours on the third day. From then on, the intake is kept at 1,000mg daily. The best source is pure orange juice with all meals, which has the added advantage of containing potassium which we lose via sweat. Lose too much, and you can get heart failure.

Zinc – Some 4,000 papers have been written about this mineral in the last 10 years. Runners lose a lot in sweat. It has a great influence on immune responses and muscular strength. Excessive tea and coffee drinking cause iron and zinc depletion. Symptoms: White spots on finger nails. Frequent infections. Skin trouble. Poor hair condition. Th best sources are: oysters, ginger root, muscle meats and all types of nuts. Zinc plays a vital role in iron absorption, so anaemia needs to be regarded as an iron and possibly zinc deficiency.

Vitamin B1 (thiamin) – This plays a crucial role in carbohydrate metabolism and energy production. In fact, when carbohydrate-boosting before a marathon, this vitamin should be increased as well. Good sources are: brown rice, which is also a low glycemic carb. and well stored as glycogen. Lentils, peas, beans, beef, pork and whole grains. Symptoms: Loss of short-term memory. Numbness and tingling in the hands and feet. Tender calf muscles. If the calf is pressed firmly with the thumb, the white spot left should disappear in ten seconds, if not, suspect a deficiency.

Frank Horwill