If I eliminate lack of sleep as the cause, I can often find that they are not eating a wide variety of foods, particularly those that are high in iron. I then do a nutritional assessment and check on their activity and health history. Certain foods enhance the absorption of iron such as meat, poultry, fish and vitamin C rich fruits and vegetables. Certain foods decrease the absorption of iron, such as oxalates in spinach, phytates in whole grains and ingredients in tea, coffee, bran and legumes. So even if tea is decaffeinated, it still contains tannin which decreases the absorption of iron - once again proving the point of moderation in everything.
Iron deficiency is more common with women than men.
Of course, if they are athletes as well, they need sufficient iron to achieve peak performance. The result of an insufficient iron intake is weakness and shortness of breath, which may impair their work and activity performance. These people are frequently pale, have a poor appetite and an increased risk of infection. Iron Supplements and Constipation Many of my clients are unaware of the fact that an iron supplement may cause constipation. Certainly, don't prescribe it for yourself.