DHA & Vit D in Pregnancy, A Key Role for Both

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The Safe Foundation for a Healthy Pregnancy

APA logoThe omega-3 DHA is an “essential” fatty acid that the body cannot produce and must be consumed through diet or supplementation. The baby must acquire its DHA from its mother, and she must obtain it by increasing the omega-3s in her daily diet or from daily supplementation.[1] International recommendations suggest that pregnant and nursing women consume 300-600mg of DHA every day to ensure that mothers remain healthy during and after pregnancy, and that their babies have every opportunity for healthy development.[2]

Fish of course remains the best source of dietary DHA, but due to concerns about toxins like mercury, many parents are opting to use nutritional supplementation from companies who ensure complete freedom from toxic elements in their fish derived oils. The incidence of mercury in fish continues to increase and represents one of the most common sources of unwanted environmental exposure.

A mothers demand for DHA increases during pregnancy, with the greatest tissue accumulation occurring in the last trimester (week 26 onwards) and then continuing in the child for the first two years of life.[3] Following birth the mothers tissue stores of DHA can remain compromised due to the transfer of her DHA via breast milk, where it is used in the continuing maturation of the babies multiple systems.[4]

Multiple pregnancies, especially if they are close together also have a detrimental impact on the maternal tissue stores of essential fatty acids.[5]

In Summary

Evidence supports the following benefits associated with optimal fish oil supplementation:

  1. Mothers are more likely to produce a baby at the end of their full term, and their baby’s weight is more likely to be within the healthy parameters.[6],[7]
  2. Mental health and mood states in mothers are more likely to remain balanced and healthy.[8]
  3. Positive development of brain tissues, visual function and the nervous system of the child are associated with optimal fatty acid status.[9],[10]

International recommendations have some congruency in recommending that pregnant and nursing mothers consume 300-600mg DHA on a daily basis to provide an optimal fatty acid pool in their tissues for the best and healthiest foetal and child development and maternal health.2

Vitamin D

For the Mother

In addition to essential fatty acids, the addition of Vitamin D into the mother’s diet has good clinical correlates. Women in the northern hemispheres have increased risk of Vit D deficiency due to lack of available sunlight exposure.[11] Vit D deficiency, confirmed via suitable blood tests is a significant risk for in utero complications. This includes; preeclampsia[12], gestational diabetes[13] and bacterial vaginitis[14].

For the Foetus & Child

There are some associated risks to developmental as well as overall health risks and benefits from optimal vitamin D status during pregnancy and in the early years. These include schizophrenia[15], autism[16], lower respiratory tract infections[17], birth weight[18], diabetes[19], seizures[20], heart failure[21], weak bones[22] and asthma[23] amongst others.

Dose Recommendations

Until we have better information on doses of vitamin D that will reliably provide adequate blood levels of 25(OH)D without toxicity, treatment of vitamin D deficiency in otherwise healthy children should be individualised according to the numerous factors that affect 25(OH)D levels, such as:

  • body weight
  • percent body fat
  • skin melanin
  • latitude
  • season of the year
  • and sun exposure

The doses of sunshine or oral vitamin D3 used in healthy children should be designed to maintain 25(OH)D levels above 50 ng/mL. As a rule, in the absence of significant sun exposure, we believe:

Most healthy children need about 1,000 IU of vitamin D3 daily per 11 kg (25 lb) of body weight to obtain levels greater than 50 ng/mL. Some will need more, and others less. In our opinion, children with chronic illnesses such as autism, diabetes, and/or frequent infections should be supplemented with higher doses of sunshine or vitamin D3, doses adequate to maintain their 25(OH)D levels in the mid-normal of the reference range (65 ng/mL) — and should be so supplemented year-round (p. 868).[24]


[1] Denomme J, Stark KD, Holub BJ. Directly quantitated dietary (n-3) fatty acid intakes of pregnant Canadian women  are lower than current dietary recommendations. J Nutr. 2005 Feb;135(2):206-11. View Abstract

[2] Simopoulos AP, Leaf A, Salem N Jr. Workshop statement on the essentiality of and recommended dietary intakes for Omega-6 and Omega-3 fatty acids. Prostaglandins Leukot Essent Fatty Acids. 2000 Sep;63(3):119-21. View Abstract

[3] Carlson,SE. American Dietetic Association Food and Nutrition Conference, Anaheim, CA. October 4, 2004.

[4] Dunstan JA, Simmer K, Dixon G, Prescott SL. Cognitive assessment of children at age 2(1/2) years after maternal fish oil supplementation in pregnancy: a randomised controlled trial. Arch Dis Child Fetal Neonatal Ed. 2008 Jan;93(1):F45-50. Epub 2006 Dec 21. View Abstract

[5] Hornstra G. Essential fatty acids in mothers and their neonates. Am J Clin Nutr. 2000 May;71(5 Suppl):1262S-9S. View Abstract

[6] Allen KG, Harris MA. The role of n-3 fatty acids in gestation and parturition. Exp Biol Med (Maywood). 2001 Jun;226(6):498-506. View Abstract

[7] Olafsdottir AS, Magnusardottir AR, Thorgeirsdottir H, Hauksson A, Skuladottir GV, Steingrimsdottir L. Relationship between dietary intake of cod liver oil in early pregnancy and birthweight. BJOG. 2005 Apr;112(4):424-9. View Abstract

[8] Freeman MP, Hibbeln JR, Wisner KL, et al. Randomized dose-ranging pilot trial of omega-3 fatty acids for postpartum depression. Acta Psychiatr Scand, 2006;113(1):31-5. View Abstract

[9] Jacobson J, Jacobson S, Muckle G, et al. Beneficial effects of a polyunsaturated fatty acid on infant development: evidence from the inuit of arctic Quebec. J Pediatr. 2008;152(3):356-64. View Abstract

[10] Singh M. Essential fatty acids, DHA and human brain. Indian J Pediatr,2005;72(3):239-242 View Abstract

[11] Lee JM, Smith JR, Philipp BL, Chen TC, Mathieu J, Holick MF. Vitamin D deficiency in a healthy group of mothers and newborn infants. Clin Pediatr (Phila). 2007 Jan;46(1):42-4. View Abstract

[12] Bodnar LM, Catov JM, Simhan HN, Holick MF, Powers RW, Roberts JM. Maternal vitamin D deficiency increases the risk of preeclampsia.J Clin Endocrinol Metab. 2007 Sep;92(9):3517-22. Epub 2007 May 29. View Abstract

[13] Zhang C, Qiu C, Hu FB, David RM, van Dam RM, Bralley A, Williams MA. Maternal plasma 25-hydroxyvitamin D concentrations and the risk for gestational diabetes mellitus. PLoS One. 2008;3(11):e3753. Epub 2008 Nov 18. View Abstract

[14] Bodnar LM, Krohn MA, Simhan HN. Maternal vitamin D deficiency is associated with bacterial vaginosis in the first trimester of pregnancy. J Nutr. 2009 Jun;139(6):1157-61. Epub 2009 Apr 8. View Abstract

[15] Kinney DK, Teixeira P, Hsu D, Napoleon SC, Crowley DJ, Miller A, Hyman W, HuangE. Relation of schizophrenia prevalence to latitude, climate, fish consumption,infant mortality, and skin color: a role for prenatal vitamin d deficiency and infections? Schizophr Bull. 2009 May;35(3):582-95. Epub 2009 Apr 8. View Abstract

[16] Glaser,G. What if Vitamin D Deficiency Is a Cause of Autism?. Scientific American, April 24, 2009. View Abstract

[17] Karatekin G, Kaya A, Salihoğlu O, Balci H, Nuhoğlu A. Association of subclinical vitamin D deficiency in newborns with acute lower respiratory infection and their mothers. Eur J Clin Nutr. 2009 Apr;63(4):473-7. Epub 2007 Nov 21. View Abstract

[18] Scholl TO, Chen X. Vitamin D intake during pregnancy: association with maternal characteristics and

infant birth weight. Early Hum Dev. 2009 Apr;85(4):231-4. Epub 2008 Nov 12. View Abstract

[19] Stene LC, Ulriksen J, Magnus P, Joner G. Use of cod liver oil during pregnancy associated with lower risk of Type I diabetes in the offspring. Diabetologia. 2000 Sep;43(9):1093-8. View Abstract

[20] Fleischman AR, Rosen JF, Nathenson G. 25-Hydroxycholecalciferol for early neonatal hypocalcemia. Occurrence in premature newborns. Am J Dis Child. 1978 Oct;132(10):973-7. View Abstract

[21] Maiya S, Sullivan I, Allgrove J, Yates R, Malone M, Brain C, Archer N, Mok Q, Daubeney P, Tulloh R, Burch M.Heart. Hypocalcaemia and vitamin D deficiency: an important, but preventable, cause of life-threatening infant heart failure. 2008 May;94(5):581-4. Epub 2007 Aug 9. View Abstract

[22] Javaid MK, Crozier SR, Harvey NC, Gale CR, Dennison EM, Boucher BJ, Arden NK, Godfrey KM, Cooper C; Maternal vitamin D status during pregnancy and childhood bone mass at age 9 years: a longitudinal study. Princess Anne Hospital Study Group.Lancet. 2006 Jan 7;367(9504):36-43. View Abstract

[23] Litonjua AA, Weiss ST.J Allergy Clin Immunol. Is vitamin D deficiency to blame for the asthma epidemic?

2007 Nov;120(5):1031-5. Epub 2007 Oct 24. View Abstract

[24] Cannell JJ, Vieth R, Willett W, Zasloff M, Hathcock JN, White JH, Tanumihardjo SA, Larson-Meyer DE, Bischoff-Ferrari HA, Lamberg-Allardt CJ, Lappe JM, Norman AW, Zittermann A, Whiting SJ, Grant WB, Hollis BW, Giovannucci E. Cod liver oil, vitamin A toxicity, frequent respiratory infections, and the vitamin D deficiency epidemic. Ann Otol Rhinol Laryngol. 2008 Nov;117(11):864-70. View Abstract

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