Vitamins are organic compounds, essential to life and required in minute amounts for normal growth, development and maintenance (Combs, 2012). Vitamins are divided into those which are either water or fat-soluble. Water-soluble vitamins include both B-complex vitamins and vitamin C. In contrast, the vitamins A, D, E and K comprise the fat-soluble group. These seaweed-derived vitamins are important dietary compounds, vital for many biological processes and contributing to better overall health.
Water-soluble Vitamins in Seaweed
Water-soluble vitamins are not stored in the body and must be replaced regularly to prevent deficiency. Vitamin B1 (Thiamine) is ubiquitous, found in all cells of the body and has important roles in carbohydrate metabolism. Thus, deficiency can lead to metabolic coma and even death.
Vitamin B1 is present in seaweeds such as Ascophyllum nodosum, Sargassum muticum, Ulva lactuca and Laminaria digitata at levels up to 30 mg/kg.
Vitamin B2 (Riboflavin) is a component of cofactors which play an important role in metabolism in addition to functioning as an antioxidant in the body. Deficiency in vitamin B2 in pets can result in retarded growth, cardiological changes, dermatitis, alopecia, ataxia and corneal degradation (National Research Council, 1987). Riboflavin is present at levels up to around 65 mg/kg in seaweeds such as Laminaria digitata.
Vitamin B3 (Niacin and Niacinamide) has a role in DNA repair and the production of some steroid hormones in the adrenal gland (Kraan, 2013). In addition, vitamin B3 can improve cholesterol levels and reduce cardiovascular risk (Bruckert et al., 2010). Deficiency in vitamin B3 can result in a disease called pellagra (black tongue disease in dogs). Symptoms of vitamin B3 deficiency include sensitivity to sunlight, alopecia, swelling, insomnia, weakness and diarrhoea.
Vitamin B6 is present in seven known forms but is most commonly known as Pyridoxine. Vitamin B6 is multifunctional, with roles in sugar and fat metabolism, neurotransmitter synthesis and regulation of some hormones. Symptoms associated with deficiency of vitamin B6 include microcytic anaemia, depression, dermatitis and high blood pressure (Kraan, 2013).
Vitamin B12 (cobalamin) cannot be produced by animals or plants and is synthesised only by bacteria (Croft et al., 2006). This vitamin is present in foods such as meat, fish and some dairy products, however, non-animal food sources of vitamin B12 are extremely scarce. Seaweeds are one of the few non-animal sources of vitamin B12. For example, consumption of just a few grams of the green seaweed, Ulva lactuca, can meet the recommended dietary allowances in Ireland for vitamin B12 (Macartain et al., 2007). As with the other B-complex vitamins, B12 has an important role in metabolism and is important for the production of red blood cells and maintenance of a healthy nervous system. Deficiency in vitamin B12 can result in anaemia, fatigue, neurological disorders and even paralysis.
Ascorbic acid, better known as vitamin C, is another water-soluble vitamin and is a well-known antioxidant. Vitamin C is a cofactor for enzymes including those involved in collagen synthesis. Vitamin C also has roles in wound healing, bone and tooth formation, strengthening of blood vessel walls, improving immune system function and the intestinal absorption of iron. On average, the level of vitamin C in seaweed is similar to the levels found in blackcurrants and peppers. For the seaweeds Sargasssum muticum, Fucus vesiculosus and Ulva spp., the concentration of vitamin C is in the approximate range of 450-9420mg/kg (Kraan, 2013).
Fat Soluble Vitamins in Seaweed
β-carotene precursor to Vitamin A
Seaweed also contains significant quantities of β-carotene, which is a precursor to the fat-soluble vitamin A. β-carotene is a carotenoid that is a strong antioxidant and has been reported to have a role in cancer prevention and reduced risk of cardiovascular disease (Holdt and Kraan, 2011).
Vitamin E, which includes tocopherols and tocotrienols, is another fat-soluble vitamin found in seaweeds such as Ascophyllum nodosum and Ulva spp. Vitamin E is also a strong antioxidant and is essential for reproduction (Brigelius-Flohe and Traber, 1999). Deficiency of vitamin E can lead to symptoms such as neuromuscular abnormalities and the highest levels of this vitamin are generally found in brown seaweeds such as Ascophyllum nodosum, Fucus spp. and Laminaria digitata.
Overall, seaweed provides a natural, fully sustainable source of various vitamins and other additional bio-active compounds which together can improve the health of your pet.