Although long chain polyunsaturated fatty acids (LC-PUFAs) are not essential nutrients at age 0-3 months, they can aid in the child's sensory development. In particular, Omega-3 docosahexaenoic acid (DHA) and Omega-6 arachidonic acid (ARA) play a big role in early human nutrition.
Vitamin D supports healthy bone development. In general, the body can synthesise vitamin D with the help of sunlight, but the amount is often insufficient to meet a baby's needs in their first year of life. Therefore, supplementation during this time is a common measure in the northern hemisphere.
Long chain polyunsaturated fatty acids (LC-PUFAs) represent nonessential nutrients that support infants' sensory development and bestow other advantages such as anti-inflammatory effects. In human nutrition, two major families of fatty acids play a role: Omega-3 and Omega-6, which differ in the position of the terminal double bond. The main Omega-3 and Omega-6 fatty acids are essential linoleic and alpha linolenic acids. In the LC-PUFA category, docosahexaenoic acid (DHA) represents the Omega-3 family of fatty acids and arachidonic acid (ARA) represents their Omega-6 counterparts.
Generally, the human body is able to synthesise LC-PUFAs – but not in sufficient amounts, especially in certain genetic arrangements. As neither cow’s milk nor vegetable oils contain LC-PUFAs, alternative oil sources are needed to ensure sufficient LC-PUFA supply. Tuna oil is an example of a source of DHA, and single cell oils (e.g. Mortierella alpina) are a source of ARA. European Food Safety Authority (EFSA) (2014a) recommends the following dosage for orientation:
Vitamin D is a semi-essential element in human nutrition because human beings are able to synthesise it in the skin with the help of Ultraviolet-B (UVB) radiation. It plays an important role in bone health due to its involvement in calcium and phosphate metabolism (SACN, 2016; EFSA, 2016). Fat-soluble vitamin D belongs to the group of calciferols that can be further divided into two types: plant-based vitamin D2 (ergocalciferol); and vitamin D3 (cholecalciferol), which is of animal origin.
Vitamin D consumed in its natural form in food is absorbed with fat and transported out of the gut as a part of chylomicrons (lipoprotein particles). Its absorption rate is around 80%. This vitamin is synthesised in human skin out of 7-Dehydrocholesterol under the influence of sunlight (UVB radiation; wavelengths between 280-320nm). Newborns naturally obtain vitamin D from sunlight and breast milk, but the concentrations are often low – dependent on geographical and climate conditions, and the mother’s nutrition. Geographical and climate conditions include latitude, time of the year, time of day, and length of sunshine hours together with duration of sun exposure. Further factors include the usage of protective sun care and clothing, degree of skin pigmentation, and skin thickness. During summer months, it is possible to achieve the necessary endogenous synthesis through sunlight alone – even in the northern hemisphere. Vitamin D3 that has been synthesised with sunlight can be stored and used during the winter period. Nevertheless, the risk remains of developing hypovitaminosis D (vitamin D deficiency) as these reserves are generally insufficient. Hypovitaminosis D is associated with impaired bone mineralisation (causing rickets in children and osteomalacia in adults), seizures, and breathing difficulty (EFSA, 2016).
Therefore, particularly in the northern hemisphere, prophylactic supplements are used to ensure adequate vitamin D concentrations. For example, in Germany, infants receive vitamin D supplements from the first week of age until the end of their first year – regardless of whether the child is breastfed or bottle-fed. This prophylaxis is usually done independently of endogenous vitamin D synthesis and vitamin D intake through breast milk or formula. Even during the second year of life, vitamin D supplementation is often continued, but only during the winter months. Care should be given to avoid excessive vitamin D administration, as this could lead to hypercalcaemia, resulting in soft tissue calcification and renal, as well as cardiovascular, damage (Vieth, 1999; Zitterman and Koerfer, 2008). No evidence exists to support vitamin D supplementation for health benefits other than calcium and phosphate metabolism, and bone health (Braegger et al, 2013).
Recommended vitamin D intake dosages (excluding endogenous synthesis) are:
DGE (2015), Institute of Medicine (US) (2011), Yu et al (2017):