The phrase "a source of essential" is not complete and lacks clarity in written English.
It can be used when referring to something that provides necessary or fundamental elements, but it needs to be followed by a noun to convey a complete thought.
Example: "Water is a source of essential nutrients for all living organisms."
Alternatives: "a provider of vital" or "a supplier of crucial".
Sometimes Gawker felt like a source of essential, exclusive information, tailored to the needs of people just like me.
For decades, microbes had been a source of essential pharmaceuticals: chemotherapies, blood thinners, and drugs crucial to organ transplants.
In effect, the value of manure as a mulching material may be greater than is its value as a source of essential plant nutrients.
Dietary protein is a source of essential amino acids and energy for prawn larvae.
Salvia sclarea is one of the most important aromatic plants cultivated world-wide as a source of essential oils.
In this study, we evaluated the marine resource E. linze as a source of essential oil for use as a strong antibacterial agent that can efficiently control against the Gram negative bacteria E. coli and S. Typhimurium.
Callistemon viminalis is also used for weed control, as bioindicator for environmental management, and is a source of an essential oil [6].
We previously reported on a de novo designed protein "milk bundle-1Trp" (MB-1Trp) as a source of selected essential amino acids (EAA) for ruminant feeding.
According to the US Justice Department, China is a source of the essential chemicals needed in the production of drugs like MDMA.
Although lactating women consumed ~70% of their protein from animal products, which is also a source of other essential nutrients, the animal foods usually contain a high content of saturated fatty acid (SFA's).
The most prudent approach is to recommend a daily intake of fruits and vegetables as a likely source of essential nutrients.
