Macro minerals are essential chemical elements that the human body requires in amounts greater than 100 milligrams per day. Unlike trace elements needed in tiny doses, these major minerals build physical structures and keep vital fluid systems working properly. During pregnancy and lactation, maternal demand for macro minerals rises sharply to support the expanding blood volume, developing fetal skeleton, and breast milk production. Calcium, magnesium, sodium, potassium, and phosphorus form this critical group of nutrients. Midwives caring for pregnant women in Nigeria must look beyond basic calorie intake to ensure these mineral building blocks are adequately supplied through local foods or appropriate supplementation.
Phosphorus is the second most abundant mineral in the human body, working closely with calcium to build strong bones and teeth. Beyond structural support, phosphorus plays a non-negotiable role in cellular energy metabolism through adenosine triphosphate, forms the backbone of genetic material like DNA and RNA, and helps maintain the body's acid-base balance. For the developing fetus, adequate phosphorus is vital for proper organogenesis and skeletal mineralization. In the pregnant mother, it prevents muscle weakness and supports efficient oxygen transport by red blood cells.
Phosphorus is widely distributed in plant and animal foods, making severe dietary deficiency rare in populations with varied diets. Pregnant women in Nigeria can easily meet their daily requirements by consuming locally available foods rich in this mineral.
The small intestine absorbs dietary phosphorus passively and through active transport regulated by the active form of vitamin D. Once inside the bloodstream, phosphorus levels are tightly controlled by the kidneys, parathyroid hormone, and fibroblast growth factor 23. If blood levels rise, the kidneys filter out the excess and excrete it through the urine. Conversely, when blood levels drop, the kidneys reduce excretion to conserve the mineral. This delicate balancing act ensures that maternal and fetal cells always have a stable supply without disrupting the body's internal chemistry.
Although clinical deficiency of phosphorus is uncommon because the mineral is present in almost all foods, prolonged starvation, severe malnutrition, or excessive use of aluminum-containing antacids can trigger hypophosphatemia. This deficiency causes generalized muscle weakness, bone pain, and respiratory failure, which compromises both mother and fetus. On the other hand, chronic excess phosphorus, often driven by high consumption of processed foods and soft drinks containing phosphate additives, can impair calcium balance and lead to long-term cardiovascular risks. Midwives must educate pregnant women on eating wholesome, natural foods rather than relying on processed convenience items.