The DIAMOND (DHA Intake And Measurement Of Neural Development) Study: a double-masked, randomized controlled clinical trial of the maturation of infant visual acuity as a function of the dietary level of docosahexaenoic acid.
BACKGROUND
The range of human milk docosahexaenoic acid (DHA) concentrations worldwide is much broader than the range explored in randomized clinical trials to date.


OBJECTIVE
The primary objective was to determine the effect of 4 amounts of DHA supplementation on the visual acuity of formula-fed infants at 12 mo of age. Secondary objectives were to evaluate visual acuity maturation, red blood cell fatty acids, tolerance, anthropometric measures, and adverse events.


METHODS
This double-masked, randomized trial was conducted at 2 sites (Dallas and Kansas City). Three hundred forty-three healthy, term, formula-fed infants were enrolled at 1-9 d of age and were randomly assigned to be fed 1 of the following 4 infant formulas containing equivalent nutrient amounts, except for long-chain polyunsaturated fatty acids: control (0% DHA), 0.32% DHA, 0.64% DHA, or 0.96% DHA; DHA-supplemented formulas also provided 0.64% arachidonic acid. Visual acuity was measured by visual evoked potentials in 244 infants who completed the 12-mo primary outcome examination.


RESULTS
Infants fed control formula had significantly poorer visual evoked potential visual acuity at 12 mo of age than did infants who received any of the DHA-supplemented formulas (P < 0.001). There were no significant differences in visual evoked potential visual acuity between the 3 amounts of DHA supplementation for either site at any age tested.


CONCLUSIONS
DHA supplementation of infant formula at 0.32% of total fatty acids improves visual acuity. Higher amounts of DHA supplementation were not associated with additional improvement of visual acuity. This trial was registered at clinicaltrials.gov as NCT00753818.
Birch
Eileen E
EE
Retina Foundation of the Southwest, Dallas, TX 75231, USA. ebirch@retinafoundation.org
Carlson
Susan E
SE
Hoffman
Dennis R
DR
Fitzgerald-Gustafson
Kathleen M
KM
Fu
Valeria L N
VL
Drover
James R
JR
Castañeda
Yolanda S
YS
Minns
Laura
L
Wheaton
Dianna K H
DK
Mundy
David
D
Marunycz
John
J
Diersen-Schade
Deborah A
DA
D016718:Arachidonic Acid / Q000008:administration & dosage; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage*; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D004311:Double-Blind Method; D005074:Evoked Potentials, Visual / Q000187:drug effects*; D005260:Female; D006801:Humans; D041943:Infant Formula; D007231:Infant, Newborn / Q000254:growth & development* / Q000502:physiology; D008297:Male; D055495:Neurogenesis / Q000187:drug effects*; D014481:United States; D014785:Vision, Ocular / Q000187:drug effects* / Q000502:physiology; D014792:Visual Acuity / Q000187:drug effects* / Q000502:physiology
D004041:Dietary Fats; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid