Phyllo dough: enriched wheat sheets with more salt than the target

A 12-week randomized trial gave 142 Dutch adults aged 50 to 75 either plain bread or bread fortified with 138 mcg of folic acid and 9.6 mcg of vitamin B-12 a day. The fortified bread raised serum folate by 45 percent (6.3 nmol/L, 95% CI 4.5 to 8.1). That bread also carried B-12, and nobody in the trial ate phyllo. The link to phyllo is the flour. The USDA record lists 137 mcg DFE of folate, 0.541 mg of thiamin and 3.21 mg of iron per 3.5 oz (100 g), a profile that points to enriched wheat flour, so brands made with unenriched flour will be lower. Per 100 g the dough has 299 calories and 483 mg of sodium, before any butter or oil is brushed on.

The numbers, per 3.5 oz (100 g)

How much is actually in it

• The USDA phyllo record carries 137 ug DFE folate, 0.541 mg thiamin and 3.21 mg iron per 3.5 oz (100 g), levels that come from enriched wheat flour. — USDA SR Legacy food Phyllo dough (FDC 172791) (n = 1 record) Evidence E source
  Per 100 g: folate 137 ug DFE, thiamin 0.541 mg, riboflavin 0.341 mg, niacin 4.073 mg, iron 3.21 mg, selenium 23.3 ug; vitamin B12, vitamin C, vitamin D and cholesterol 0

What a real portion looks like

• USDA lists phyllo dough at 299 calories, 52.6 g carbohydrate, 6.0 g fat and 483 mg sodium per 3.5 oz (100 g), so a 1 oz (28.4 g) portion carries about 85 calories and 137 mg sodium. — USDA SR Legacy food Phyllo dough (FDC 172791, NDB 18338), Baked Products (n = 1 record) Evidence E source
  Per 100 g: 299 calories, protein 7.1 g, fat 6.0 g, saturated fat 1.47 g, carbohydrate 52.6 g, fiber 1.9 g, sugars 0.18 g, sodium 483 mg; 1 oz 28.4 g = 85 calories, 137 mg sodium

What your body absorbs

• According to NIH ODS, at least 85% of the folic acid added to fortified foods is absorbed when eaten with food, against about 50% of folate that occurs naturally in food. — general population, Food and Nutrition Board DFE definition Evidence E source
  Folic acid with food at least 85% bioavailable; natural food folate about 50%; 1 ug DFE = 0.6 ug folic acid from fortified foods
• In a crossover RCT in 8 ileostomy patients, less than 10% of a 200 ug folate dose baked into bread was left unabsorbed, pointing to almost complete absorption. — healthy ileostomists (n = 8), single doses of fortified whole-meal bread or breakfast (n = 8) Evidence B source
  Stomal folate under 10% of the ingested dose

What it does to your health

• A meta-analysis of before-and-after data from 30 studies found mandatory folic acid fortification of grain raised serum folate by 15.0 nmol/L and cut folate deficiency sharply. — populations in countries with mandatory grain fortification, 30 articles (n = 30 articles) Evidence C source
  Serum/plasma folate MDM 15.0 nmol/L (95% CI 9.4 to 20.5); insufficiency mPR 0.17 (95% CI 0.08 to 0.37); deficiency mPR 0.08 (95% CI 0.03 to 0.23)
• Observational data from 17 cohorts with over 875,000 people found refined grain intake was not linked with cardiovascular disease (HR 1.08, 95% CI 0.99-1.18). — 17 prospective cohort studies (>875,000 participants) (n = >875,000) Evidence C source
  CVD HR 1.08 (95% CI 0.99-1.18; 9 cohorts); stroke HR 1.06 (0.92-1.23); heart failure HR 0.95 (0.77-1.16)

Safety, limits and interactions

• In a crossover RCT in 15 young women, adding 144 ug folic acid to 3.5 oz (100 g) of white bread did not change zinc absorption (38.8% vs 40.6% at low zinc, 26.7% vs 22.7% at high zinc). — 15 healthy women (22-33 y), four single meals two weeks apart (n = 15) Evidence B source
  Zinc absorption 38.8% vs 40.6% (P = 0.74) at 1.2 mg zinc; 26.7% vs 22.7% (P = 0.16) at 3.0 mg zinc
• FDA's 2024 voluntary sodium goals name phyllo dough in the frozen dough category, with a target mean of 290 mg and an upper bound of 420 mg sodium per 3.5 oz (100 g), against a 2022 baseline of 384 mg. — frozen dough sold in the US (category 86), 14 products in the 2022 baseline (n = 14 products) Evidence E source
  Baseline 384 mg/100 g; Phase II target mean 290 mg/100 g; upper bound 420 mg/100 g; USDA phyllo record 483 mg/100 g

Who this works differently for

• In a 12-week RCT in 142 adults aged 50 to 75, bread fortified with 138 ug folic acid and 9.6 ug vitamin B-12 a day raised serum folate by 45% and serum vitamin B-12 by 49%. — Men and women aged 50-75 y, the Netherlands, fortified bread (n = 72) or unfortified bread (n = 70), 12 weeks (n = 142) Evidence B source
  Serum folate +45% (6.3 nmol/L; 95% CI 4.5 to 8.1); serum B-12 +49% (102 pmol/L; 95% CI 82 to 122)
• Registry data reviewed across nine countries link folic acid fortification of flour with fewer neural tube defects, with Chile falling from 18.6 to 7.3 per 10 000 births between 1999 and 2007. — live births and stillbirths, Chile, Argentina, Brazil, Canada, Costa Rica, Iran, Jordan, South Africa and the USA; 27 studies (n = 27 studies) Evidence C source
  Chile NTD prevalence 18.6 to 7.3 per 10 000 births (1999-2007); Costa Rica about 60% reduction

The bottom line

Folic acid added to flour is absorbed well. The NIH Office of Dietary Supplements puts it at 85 percent or more when eaten with food, against about 50 percent for folate that occurs naturally. In a crossover trial in 8 healthy people with an ileostomy, under 10 percent of a 200 mcg folate dose baked into whole-meal bread came out unabsorbed. In 15 young women, zinc absorption from white bread did not differ with its folate content at either zinc level tested (38.8 against 40.6 percent, and 26.7 against 22.7 percent). Observational before-and-after data from 30 studies found that mandatory folic acid fortification of grain raised serum folate by 15.0 nmol/L (95% CI 9.4 to 20.5), with high heterogeneity between studies. Registry data from nine countries link flour fortification with fewer neural tube defects, and in Chile the rate fell from 18.6 to 7.3 per 10 000 births between 1999 and 2007. Phyllo is a minor source in that flour supply. Observational data from 17 cohorts with over 875,000 people found refined grain intake was not linked with cardiovascular disease (HR 1.08, 95% CI 0.99 to 1.18). Salt is the caution. The USDA record sits at 483 mg per 3.5 oz (100 g), above the 420 mg upper bound in FDA's 2024 draft voluntary goal for frozen dough, a category that also covers bread, pizza and puff pastry dough. A 1 oz (28.4 g) portion carries about 85 calories and 137 mg of sodium. Phyllo is wheat dough, and we have no evidence here on celiac disease, wheat allergy, children or medicines, so this page cannot speak to them.

Sources

1. phyl-r4-02 · food composition dataset
   Phyllo dough, FDC 172791: folate 137 ug DFE, thiamin 0.541 mg, riboflavin 0.341 mg, niacin 4.073 mg, iron 3.21 mg, selenium 23.3 ug per 100 g
   USDA FoodData Central, SR Legacy 2019, FDC 172791 Phyllo dough · checked 2026-10-02
2. phyl-r4-01 · food composition dataset
   Phyllo dough, FDC 172791, NDB 18338: energy 299 kcal, protein 7.1 g, fat 6.0 g, saturated fat 1.47 g, carbohydrate 52.6 g, fiber 1.9 g, sodium 483 mg per 100 g; portion 1 oz 28.4 g
   USDA FoodData Central, SR Legacy 2019, FDC 172791 Phyllo dough · checked 2026-10-02
3. phyl-r4-03 · fact sheet
   At least 85% of folic acid is estimated to be bioavailable when taken with food, whereas only about 50% of folate naturally present in food is bioavailable [1,2,4].
   NIH Office of Dietary Supplements, Folate Fact Sheet for Health Professionals · checked 2026-10-02
4. phyl-r4-06 · RCT crossover
   In a randomized crossover trial, healthy ileostomists (n = 8) ingested single doses of whole-meal bread that contained ap 450 nmol (200 micro g) of either (6S)-[(13)C(5)]5-CH(3)-H(4) folate or [(13)C(5)]folic acid or a breakfast meal that contained ap 450 nmol (200 micro g) [(13)C(5)]folic acid. ... The stomal folate content was lt 10% of the ingested dose
   Am J Clin Nutr, 2010 · checked 2026-10-02
5. phyl-r4-07 · meta-analysis of observational data
   For serum/plasma folate concentrations, the MDM across all studies was 15.0 nmol/L (95% CI: 9.4, 20.5). For serum/plasma folate insufficiency and deficiency, the mPR estimates were 0.17 (95% CI: 0.08, 0.37) and 0.08 (95% CI: 0.03, 0.23), respectively.
   J Nutr, 2026 · checked 2026-10-02
6. phyl-r4-09 · meta-analysis of cohorts
   Meta-analyses of hazard ratios (HR) and 95% confidence intervals (CI) obtained from 17 prospective cohort studies (>875,000 participants) indicated that refined grain intake was not associated with risk of CVD (HR = 1.08, 95% CI, 0.99-1.18, I2 = 70%; 9 cohorts)
   Trends Cardiovasc Med, 2024 · checked 2026-10-02
7. phyl-r4-04 · RCT crossover
   Zinc absorption was measured in 15 healthy women (22-33 y), each of whom consumed 4 single meals spaced 2 wk apart in a randomized crossover design. ... Mean (+/-SD) zinc absorption did not differ significantly in relation to the folate content of the breads at either the low zinc content (38.8 +/- 13.5% and 40.6 +/- 16.5% for A and B, respectively; P = 0.74) or the high zinc content (26.7 +/- 9.3% and 22.7 +/- 6.6% for C and D, respectively; P = 0.16).
   Am J Clin Nutr, 2001 · checked 2026-10-02
8. phyl-r4-10 · guidance
   86 Frozen Dough Frozen dough. Examples include bread dough, pizza crust dough, puff pastry sheets, phyllo dough and cinnamon roll dough. ... 14 - 384 290 420
   US FDA, Voluntary Sodium Reduction Goals, Edition 2 (draft guidance), 2024, category 86 · checked 2026-10-02
9. phyl-r4-05 · RCT
   Men and women aged 50-75 y were randomly assigned in this 12-wk double-blind, placebo-controlled trial to consume bread fortified with 138 mug folic acid and 9.6 mug vitamin B-12 daily (n = 72) or unfortified bread (n = 70). RESULTS: The consumption of fortified bread increased serum folate concentrations by 45% (mean: 6.3 nmol/L; 95% CI: 4.5, 8.1 nmol/L) and serum vitamin B-12 concentrations by 49% (mean: 102 pmol/L; 95% CI: 82, 122 pmol/L) relative to the placebo group.
   Am J Clin Nutr, 2008 · checked 2026-10-02
10. phyl-r4-08 · systematic review
    Twenty-seven studies that met inclusion criteria were evaluated. Costa Rica showed a significant reduction in NTD (∼60 %). Prevalence in Chile decreased from 18·6 to 7·3/10 000 births from 1999 to 2007
    Public Health Nutr, 2013 · checked 2026-10-02