IN AID OF GESTATION
Can supplementation fill critical nutrient gaps among pregnant Filipino women and guarantee the health of their newborns?
By Grace Roxas
Correspondent
Pregnant Filipino women are eating heavier but not necessarily better. The 2003 national survey by the Food and Nutrition Research Institute (FNRI) show that niacin and iodine are the only nutrients adequately ingested by childbearing women despite higher intakes of meat and poultry on top of the continuing preponderance of rice in the Filipino diet. The new "no deficiency" state of iodine among pregnant women and children are attributed to inroads made by the national salt-fortification program.
Intake of critical prenatal nutrients, notably iron and calcium, remains dismally low at 28.8 percent and 52.3 percent of the daily recommended energy and nutrient intakes (RENI), the new dietary standards which replaced recommended daily allowance (RDA) since 2002. While folate, another important maternity nutrient, did not fall under the ambit of the survey, the relative decline in the consumption of vegetables and fruits and low intakes of potentially folate-fortified foods like nonrice cereals and milk do not augur well. Folate, a foil against neural-tube defects (NTDs), is also not as bioavailable in its naturally occurring state as synthetic folic acid.
Racing against the biological clock
As these dismal statistics stack up against the steady rate of child conception in this country, micronutrient supplementation takes on greater urgency as a way to meet special nutritional requirements of childbearing. As a strategy to address vitamin and mineral deficiencies, it is considered more cost-effective and cost-beneficial than dietary diversification and food fortification.
In the face of high nutritional anemia prevalence (43.9 percent) among pregnant women relating not only to deficiency in iron but in other nutrients as well, the FNRI notes that the national iron-supplementation program can be reinforced by incorporating other nutrients.
Iron supplementation is now a mainstay in a pregnant woman's menu of dietary supplements. Iron is essential for hemoglobin formation in maternal and fetal tissues and ensures the carrying capacity of blood for mother and child. Since red meat and liver are the best and most readily absorbed sources of iron, this nutrient is not usually found in the pregnant Filipino woman's diet that is still basically of a rice-fish-vegetable variety. But there is a caveat against dispensing iron supplements during the first trimester because of possible adverse effects on fetal development at that stage.
The same caution applies to vitamin-A supplementation during the first trimester because it might be teratogenic in large preformed doses. A study quoted by the American Dietetic Association found that women taking more than 10,000 IU preformed vitamin A run a greater risk of having babies with cranial-neural-crest defects. Too much preformed vitamin A may also interfere with vitamin D, which is necessary for mineral homeostasis and improved absorption and utilization of calcium and phosphorus.
As an alternative, supplements where vitamin A exists mostly or wholly as its beta-carotene precursor can be taken liberally. The same goes for the many fruits and vegetables rich in beta-carotene. Beta-carotene is not toxic even at high consumption because the body transforms it to vitamin A only as needed.
Early folic-acid supplementation, at least two months prior to pregnancy, is endorsed on top of eating folate-rich food. Based on studies cited by the American Academy of Pediatrics, at least half of NTD cases can be prevented if women consume supplements before and during the early weeks of pregnancy, aside from the folate in their diet. There is said to be greater blood folate concentrations from folic-acid supplementation than from naturally occurring food folate.
For women with previous NTD-related pregnancies, folate consumption of up to four mg per day is recommended by the United States Centers for Disease Control and Prevention (CDC). But a word of warning is in order. Despite having no known toxicity, higher doses of folic acid are said to obscure pernicious anemia and interfere with anticonvulsant drugs.
Lifelong preparation
The need for periconceptional storage of iron and folate highlights the importance of a lifelong nutritional preparation for pregnancy. Dr. Regta Pichay, chair of the obstetrics and gynecology department of Manila Central University Hospital, observes that "the brain is developing in the first months when most women are not even aware that they are pregnant. So if a woman is anemic and she gets pregnant, the number of neurons formed in her baby's brain is less than those of a fetus whose mother is healthy."
She adds: "In developed countries, baby girls are prepared for pregnancies as early as two years old. If you look at some of their products, like cereals, they are already enriched with folate and iron. That's why the government should probably come up with an iron- and folate-supplementation program for every girl who reaches adolescence."
Hyperemesis or excessive vomiting during the first trimester of pregnancy also makes it impractical in some cases to administer supplements, so a woman may have to rely on her nutritional stores before conception to pull her and her evolving embryo through this critical juncture.
Other nutrients for major supplementation are calcium and DHA (docosahexaenoic acid), an omega-3 essential fatty acid primarily found in the oil of cold-water fish and ascribed with properties for promoting brain growth and improving visual acuity of the baby.
In fetal skeleton and dental development, an adequate supply of calcium in the mother's bones decreases risk of maternal osteoporosis later in life by preventing calcium "cannibalism," which occurs when the fetus has to tap the maternal bone calcium due to lack of extra calcium reserves.
Reality check
While most standard vitamins and minerals needed by pregnant women can probably be obtained with a proper diet plan, and the complex matrix of natural food contains modes of beneficial interaction not easily replicated synthetically, social and marketplace realities push the trend toward more of either supplementation or food fortification.
One of these realities is the nutrient-stripping effect of the different stages of modern food production, from planting in nutrient-poor soil and nurturing with nonorganic fertilizers and pesticides, to steeping food in preservatives and additives to enhance shelf life and other superficial qualities.
"If you planted what you ate, the way it was during our forefathers' time, you can get the nutrients you need from food. But with the way our food is delivered now--and I don't see the system improving in the next few years--we would have to resort to more supplementation," says Dr. Rebecca Singson of the Makati Medical Center.
Poverty and limited access to organically grown and optimum food is another reality. "Diet diversification can probably work for the classes A, B, and C. But most of our population would be the lower C, D, and E who need all the nutrients they can get and are the least prepared for their pregnancies," says Pichay.
Organically grown food is more expensive because they are harder to grow and perishes faster. And in the absence of indigenous substitutes, some optimal sources of prenatal nutrients may simply be inaccessible to the average Filipino woman on a regular basis. Singson cites a finding that in order to get enough essential fatty acids for the baby's brain growth, a pregnant woman has to eat a lot of salmon and codfish, both good sources of fish oil but very rarely found in the local diet.
Single preparations containing supplementary amounts of standard micronutrients are thus dispensed as a nutritional safety net and to capture trace elements like zinc and selenium that are rarely met with in the average Filipino diet but have roles to play in prenatal health. A multiple micronutrient preparation recommended by the Department of Health includes vitamins A, B1, B2, B6, B12, niacin, vitamin C, D, E, copper, folic acid, iodine, iron, selenium, and zinc.
But as the growing need to supplement spawns a multiplicity of valid options from both commercial and government channels, it also opens new avenues of interactions (nutrient-nutrient, drug-nutrient) for good or ill where research will be hard put to keep up. Wise food choices should therefore remain the bedrock of good prenatal nutrition.
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