Water-soluble vitamins: Part 1

In the following audio clip, Konstantinos Gerasimidis introduces this step and the key areas we will cover.

The transcript for this audio can be found here or in the downloads section below.

Water-soluble vitamins are essential for whole body function and homeostasis.

There are few conclusive studies to determine the optimal intakes of water-soluble vitamins for preterm infants. The ESPGHAN committee on nutrition (CoN) produced recommendations for preterm infants using a multifaceted approach.

The concentrations of water-soluble vitamins in human breastmilk provide the basis to estimate daily recommendations for healthy full-term infants. Intakes can also be estimated using the amount provided by preterm infant formula when fed at a minimum energy intake of 115 kcal/kg/day.

The ESPGHAN CoN also presented data on the European Food Safety Authority (EFSA) daily recommendations for infants under 6 months. In general, recommendations from EFSA for term infants are likely to also be adequate for preterm infants. This is because their lower starting weight ensures an approximately 3-to-5-fold increased intake per kg body weight. However, in some instances, preterm infant requirements may differ.

It is important to recognise that these concentrations cover a wide range and some intakes may be higher than needed, which is unlikely to be beneficial. However, rapidly growing preterm infants may have greater requirements.

For each water-soluble vitamin, we will summarise some key information before providing additional details below. We begin with Thiamine (B1):

If you require a screen-reader compatible version this is available as a PDF.

Thiamine intakes are critically related to overall energy intakes. In human milk, thiamine is mainly present as thiamine monophosphate (TMP) and free thiamine. Maternal thiamine intake only influences breastmilk thiamine concentration in the event of deficiency. Breastmilk thiamine concentrations increase with lactation duration, and may be higher in mothers delivering at term.

Whole blood thiamine diphosphate (TDP) levels decline with postnatal age. Low birth weight is linked to low vitamin TDP levels, but studies suggest that current intakes are likely to be sufficient.

If you require a screen-reader compatible version this is available as a PDF.

Pantothenic acid is a component of coenzyme A and acyl-carrier proteins, and serves in acyl-group activation and transfer.

Breastmilk pantothenic acid content varies significantly between preterm and term infant mothers. Pantothenic acid concentration in breastmilk correlates with maternal intake and urinary excretion. No published evidence can currently determine the precise requirements for preterm infants.

If you require a screen-reader compatible version this is available as a PDF.

Biotin co-factor enzymes play critical roles in fatty acid synthesis, branched-chain amino acid catabolism and gluconeogenesis.

Like pantothenic acid, biotin concentration varies considerably (more than 20-fold) in breastmilk from mothers of both term and preterm infants.

If you require a screen-reader compatible version this is available as a PDF.

Niacin is a precursor of the co-enzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). NAD and NADP are involved in oxidation/reduction reactions and both catabolic and anabolic processes.

Niacin concentration in human breastmilk increases throughout lactation in mothers of both preterm and full-term infants. There are no good studies to estimate precise requirements for preterm infants.

If you require a screen-reader compatible version this is available as a PDF.

Vitamin C has several important roles, including:

• Collagen biosynthesis
• Synthesis of carnitine and catecholamines
• Metabolism of cholesterol to bile acids

Human milk vitamin C concentrations reflect maternal intake. However, low versus high vitamin C supplementation showed no significant benefits or harmful effects on oxygen requirements or retinopathy of prematurity in preterm infants.

Conclusions and recommendations:

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