Due to the reproductive life of the female body, a woman's nutritional needs differ greatly to man's. Generally, women need greater amounts of certain nutrients, particularly iron and calcium. In addition, at certain stages in a woman's life (menstruation, pregnancy, lactation and menopause for example) a woman will have increased nutritional demands.

Food and premenstrual syndrome (PMS)

The types and amounts of hormones in a woman's body will vary according to her menstrual cycle. As most woman will tell you, this hormonal variation can impact not only her body but her state of mind and emotional balance.

• Energy intakes are generally higher in the premenstrual phase and some women also have food cravings as their period approaches.
• Eating high protein foods every few hours can often temper or stop the cravings (this should not be done at the expense of other food groups, especially carbohydrates, which should form the basis of the diet.
• Fluid retention is common in the days leading up to a woman's period because certain hormones encourage the body to hold salt (sodium). The more sodium the body holds, the more fluid is retained in the tissues.
• Other common symptoms of premenstrual syndrome (PMS) include moodiness, tiredness and constipation.
• Light to moderate exercise, such as a 30-minute brisk walk each day, has also been shown to noticeably reduce symptoms of PMS.

Iron and anaemia

Haemoglobin is the compound that carries oxygen in the blood. Iron is an important mineral that works with other substances to create Haemoglobin.

• Women and men metabolise iron from food at roughly the same rate. However, while men need around 8mg of iron in their daily diet, women need up to 18mg (or 27mg if pregnant).
• Iron deficiency is the most common nutrient deficiency in women. Insufficient iron can lead to anaemia. Common symptoms include tiredness and breathlessness.
• Iron deficiency in pregnant women increases the risk of having a premature or low birth weight baby, which can have a negative impact on the short and long-term health of the baby.
• Iron absorption can be impaired by very high fibre diets, alcohol, the tannic acid in tea and concentrated sources of calcium (for example, calcium supplements)
• Good sources of iron include: Red meat, chicken and fish, fortified cereals, egg yolks, legumes and nuts, leafy green vegetables.

Vitamins, minerals and pregnancy

Pregnancy is a very important time and special attention should be paid to several nutrients:

• Calcium — include at least two serves of dairy products or equivalent high calcium foods daily. Good sources of calcium include milk, cheese, yoghurt and fish with edible bones (for example, salmon and sardines).
• Folic acid (folate) — extra folic acid is needed for the development and growth of new cells. Folate is present in a variety of vegetables and fruits as well as legumes, nuts, yeast extracts such as Vegemite and fortified foods such as bread and some breakfast cereals.
• Iron — iron requirements increase significantly during pregnancy. Anaemia is the most common nutritional deficiency during pregnancy. The best source of iron is red meat, with smaller amounts in chicken and fish. Iron is also present in plant foods such as legumes, nuts, wholegrain breads and cereals and green leafy vegetables, but it is not absorbed as well from these foods. Eating foods rich in Vitamin C at the same time can improve iron absorption. Iron supplements are frequently prescribed for pregnant women.
• Zinc — is needed to maintain the health of cells. Taking iron supplements may interfere with the absorption of zinc so women taking iron supplements should continue to eat iron-rich foods, which are also a good source of zinc.
• Iodine — iodine is needed for normal mental development of the baby but it can be difficult to get enough from food. Ways of increasing iodine intake include using iodised salt, eating fish and seafood weekly (see your health professional for advice about safe types and amounts of fish) or using a multivitamin supplement that contains iodine and is safe for pregnancy.
• Vitamin C — vitamin C is important for normal gum, tooth, bone and body tissue formation. The best source of Vitamin C is an orange, but it is also found in other citrus fruits and a variety of vegetables.

Nutrition during breastfeeding

Breastfeeding is another important time when the body is working hard to provide nutrients for both mother and child.

• Particular attention needs to be paid to protein, calcium, iron, vitamins and fluids.
• The best advice is to eat a variety of foods from each of the key food groups each day.
• Women who were anaemic during pregnancy should pay special attention to iron-rich foods as they will need to replete their iron stores.
• It may be necessary to continue taking iron supplements — be advised by your doctor.

Calcium and osteoporosis

Osteoporosis is a disorder characterised by a thinning of the bones until they are weak and easily fracture or break. Women are at greater risk of developing osteoporosis than men, particularly after menopause, because oestrogen levels are reduced. There are many factors involved, for example:

• Low calcium intake during the growing years — this increases the susceptibility to osteoporosis later in life. Bone strength in later life depends on the development of bones earlier in life. Adequate calcium intake during youth is essential to achieve peak bone mass.
• Diet — salt, caffeine and alcohol may interfere with the balance of calcium in the body by affecting the absorption of calcium. Moderate alcohol intake (1–2 standard drinks per day) and moderate tea, coffee and caffeine-containing drinks (no more than six cups per day) are recommended. Avoid adding salt at the table and in cooking.
• Exercise — or the lack of it, can also affect the development of osteoporosis.
• Low body weight — maintaining a low body weight (body mass index less than 18) has been associated with the development of osteoporosis.

Vitamin D and calcium

Vitamin D is very important because it helps calcium absorption in the body. It is also required for healthy bone metabolism. Most people will unkowingly use the sun as their main source of vitamin D. Anyone with low levels of exposure to sunlight (or those with naturally very dark skin are) at risk of vitamin D deficiency.

• Those affected may include women who cover most of their body when outdoors, shift workers, those who are unable to regularly get out of their house or women in residential care. Women who have certain medical conditions or are on some medications may also be affected.
• Balance adequate vitamin D levels with the risk of skin cancer (from too much sun exposure)
• A sensible balance of sun protection and exposure can ensure that women are not at risk of vitamin D deficiency.
• Good dietary sources of vitamin D are margarine, eggs and oily fish (such as mackerel and sardines).
• Good sources of calcium include dairy foods, calcium-fortified soymilk and sesame seeds. For women who can't eat these foods, calcium supplements may be desirable.

Remember

• Low intakes of dietary iron and calcium are common in women
• Menstruation, pregnancy, breastfeeding and menopause are times of increased nutritional demand.
• Vitamin B6 can help ease the symptoms of premenstrual syndrome
• Large quantities of foods like tea, alcohol, caffeine and salt can interfere with the absorption and excretion of important minerals.

Source: www.betterhealth.vic.gov.au

If you need help:

Contact your doctor or an accredited practising dietitian, contact the Dietitians Association of Australia.